G3500C and G3500E Generator Sets-Maintenance Intervals

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G3500C and G3500E GENERATOR SETS

Maintenance Intervals

Excerpted from Operation & Maintenance Manual (SEBU7681-14-00)

®© 2009 CaterpillarAll Rights Reserved

®

SEBU7681-14 67Maintenance Section

Maintenance Recommendations

MaintenanceRecommendations

i01135057

General MaintenanceInformationSMCS Code: 4450; 7000

Note: Read the warnings and read the instructionsthat are contained in the Safety Section of thismanual. These warnings and instructions must beunderstood before you perform any operation or anymaintenance procedures.

Rotating electric machines are complex structuresthat are exposed to the following forms of stress:

• mechanical

• electrical

• thermal

• environmental

These stresses may be of varying magnitudes. Theinsulation systems are very susceptible to damagethat is caused by the stresses that are listed above.Exposure to these stresses may shorten the effectivelife of the insulation system. Therefore, the servicelife of an electric machine will largely depend on theserviceability of the insulation systems. An inspectionprogram and a testing procedure are recommended.An inspection program and a testing procedurewill ensure that the equipment is maintained insatisfactory condition. This will increase fieldreliability.

A regular maintenance and inspection program canprovide an evaluation of the present condition ofthe equipment. A regular maintenance programand a regular inspection program can also revealfuture problems. The frequency of this maintenanceprogram will depend on the following factors:

• application

• environmental conditions

• operator's experience

• operator's philosophy

A regular maintenance program is stronglyrecommended. This program would involve thefollowing steps:

• periodic disassembly

• knowledgeable visual examination of theequipment

• the application of electrical tests

Never perform a test over the rated potential. Thesetests can damage insulation that is contaminatedor insulation that is in marginal condition. For moreinformation, refer to “I.E.E.E. Standard 432-1992” orconsult a Caterpillar dealer.

Space HeatersThe SR4B generator is capable of operating in highhumidity conditions without problems. However,problems can occur when the generator is idle andthe surrounding air is warmer than the generator.Moisture can form on the windings that will result inpoor performance from the windings. Moisture canalso result in damage to the windings. Whenever thegenerator is not active, ensure that the space heatersare in operation.

Whenever the generator is operating, ensure that thespace heaters are disconnected.

An external source of either 115 VAC or 230 VAC isrequired to operate the space heaters.

g00556903Illustration 42Space heater connection to external source (H1), (H2), (H3), and(H4) terminals.

If a 115 VAC source is available, connect bothheaters in parallel across the source. If a 230 VACsource is available, connect both heaters in seriesacross the source. Refer to Illustration 42.

68 SEBU7681-14Maintenance SectionMaintenance Recommendations

i02909163

System Pressure ReleaseSMCS Code: 1250; 1300; 1350; 5050

Coolant System

Pressurized system: Hot coolant can cause seri-ous burn. To open cap, stop engine, wait until ra-diator is cool. Then loosen cap slowly to relievethe pressure.

To relieve the pressure from the coolant system, turnoff the engine. Allow the cooling system pressure capto cool. Remove the cooling system pressure capslowly in order to relieve pressure.

Fuel SystemTo relieve the pressure from the fuel system, turn offthe engine.

High Pressure Fuel Lines (If Equipped)

Contact with high pressure fuel may cause fluidpenetration and burn hazards. High pressure fu-el spray may cause a fire hazard. Failure to fol-low these inspection, maintenance and service in-structions may cause personal injury or death.

The high pressure fuel lines are the fuel lines thatare between the high pressure fuel pump and thehigh pressure fuel manifold and the fuel lines that arebetween the fuel manifold and cylinder head. Thesefuel lines are different from fuel lines on other fuelsystems.

This is because of the following differences:

• The high pressure fuel lines are constantly chargedwith high pressure.

• The internal pressures of the high pressure fuellines are higher than other types of fuel system.

Before any service or repair is performed on theengine fuel lines, perform the following tasks:

1. Stop the engine.

2. Wait for ten minutes.

Do not loosen the high pressure fuel lines in order toremove air pressure from the fuel system.

Engine OilTo relieve pressure from the lubricating system, turnoff the engine.

i03642798

Welding on Engines withElectronic ControlsSMCS Code: 1000

NOTICEBecause the strength of the frame may decrease,some manufacturers do not recommend welding ontoa chassis frame or rail. Consult the OEM of the equip-ment or your Caterpillar dealer regarding welding ona chassis frame or rail.

Proper welding procedures are necessary in orderto avoid damage to the engine's ECM, sensors,and associated components. When possible,remove the component from the unit and thenweld the component. If removal of the componentis not possible, the following procedure must befollowed when you weld on a unit that is equippedwith a Caterpillar Electronic Engine. The followingprocedure is considered to be the safest procedure toweld on a component. This procedure should providea minimum risk of damage to electronic components.

NOTICEDo not ground the welder to electrical componentssuch as the ECM or sensors. Improper grounding cancause damage to the drive train, the bearings, hy-draulic components, electrical components, and othercomponents.

Do not ground the welder across the centerline of thepackage. Improper grounding could cause damage tothe bearings, the crankshaft, the rotor shaft, and othercomponents.

Clamp the ground cable from the welder to the com-ponent that will be welded. Place the clamp as closeas possible to the weld. This will help reduce the pos-sibility of damage.

Note: Perform the welding in areas that are free fromexplosive hazards.

1. Stop the engine. Turn the switched power to theOFF position.



2. Disconnect the negative battery cable from thebattery. If a battery disconnect switch is provided,open the switch.

3. Disconnect the J1/P1 and J2/P2 connectors fromthe ECM. Move the harness to a position that willnot allow the harness to accidentally move backand make contact with any of the ECM pins.

g01075639Illustration 43

Use the example above. The current flow from the welder tothe ground clamp of the welder will not cause damage to anyassociated components.

(1) Engine(2) Welding electrode(3) Keyswitch in the OFF position(4) Battery disconnect switch in the open position(5) Disconnected battery cables(6) Battery(7) Electrical/Electronic component(8) Minimum distance between the component that is being welded

and any electrical/electronic component(9) The component that is being welded(10) Current path of the welder(11) Ground clamp for the welder

4. Connect the welding ground cable directly to thepart that will be welded. Place the ground cable asclose as possible to the weld in order to reduce thepossibility of welding current damage to bearings,hydraulic components, electrical components, andground straps.

Note: If electrical/electronic components are usedas a ground for the welder, or electrical/electroniccomponents are located between the welder groundand the weld, current flow from the welder couldseverely damage the component.

5. Protect the wiring harness from welding debrisand spatter.

6. Use standard welding practices to weld thematerials.


i03643560

Generator Start-up ChecklistSMCS Code: 4450

Table 14

GENERATOR START-UP CHECKLIST

RATING INFORMATION

Engine Serial Number: ___________________________________ Arrangement Number: ___________________

Generator Serial Number: _________________________________ Arrangement Number: ___________________

GENERATOR NAME PLATE INFORMATION

Voltage: ___________________ Package (prime, continuous, standby): _________________

Amperage: _________________ Kilowatts: ________________________________________

Storage Location:

Generator Alignment:

Main Stator Megohmmeter Reading: Before Storage: After Storage:

Generator dried for 24 hours prior to start-up? (Y/N) Drying method:

SPACE HEATERS Yes No Comments

Space heaters operating properly?

Space heater operated 48 hrs. beforestart-up?

MEGOHMMETER TEST (SEHS9124) 30 sec.reading

60 sec.reading

30 sec.corrected

60 sec.corrected

Ambienttemp.

Comments

Main Stator

Main Rotor

Exciter Stator

Exciter Rotor

Beginning ofStorage

PMG Stator

Main Stator

Main Rotor

Exciter Stator

Exciter Rotor

Start-up

PMG Stator

Regulator Voltage Amps Comments

F1 to F2 DC

20 to 22 AC

20 to 24 AC

22 to 24 AC

26 to 28 AC

26 to 30 AC

No Load

28 to 30 AC(continued)



(Table 14, contd)

GENERATOR START-UP CHECKLIST

Generator Excitation NamePlate Information:

DC Compare with F1 to F2

F1 to F2 DC

20 to 22 AC

20 to 24 AC

22 to 24 AC

26 to 28 AC

26 to 30 AC

Full Load

28 to 30 AC


Table 15

GENERATOR START-UP CHECKLIST (CONT.)

ELECTRICAL Yes No Comments

Unit properly grounded

Check diodes

Over current protection

Over voltage protection

Check for loose wiring

Adjust voltage

Adjust frequency

Verify kilowatt transducer (if applicable)

MECHANICAL Data Comments

Bearing temperature readings at full load Front __________ Rear ___________

Stator temperature readings at full load A0 _______ B0 _______ C0 _______

Air gap on main stator Top __________ Bottom __________

Air gap on exciter stator Top __________ Bottom __________

Air gap of PMG Top __________ Bottom __________

Ambient air to generator at full load Temperature ____________________

Supplier air opening to generator Size of Opening _________________

SWITCH GEAR/PARALLEL OPERATION

Manufacturer:

Setting 1 Setting 2 Setting 3 Comments

Circuit breaker type

Overload setting

Reverse power relay

VAR/PF Controller

Load share

INSTALLATION & LOAD INFORMATION

Neutral grounding system UPS

Enclosure type Size

Motor: Other loads:

- Total SKVA - Lighting

- Total HP - Computers

- Welding

- Non-linear

- Other

FULL LOAD DATA

Voltage Amps kW KVARS P.F.


Maintenance Interval Schedule

i03675808

Maintenance Interval Schedule(Standard for G3500EGenerator Sets)SMCS Code: 1000; 4450; 7500

S/N: GZG1-Up

S/N: GZH1-Up

S/N: HAL1-Up

S/N: SSR1-Up

S/N: GAS1-Up

S/N: NGS1-Up

S/N: GTX1-Up

S/N: SLY1-Up

S/N: SXY1-Up

Ensure that all safety information, warnings andinstructions are read and understood before anyoperation or any maintenance procedures areperformed.

The user is responsible for the performance ofmaintenance, including all adjustments, the use ofproper lubricants, fluids, filters, and the replacementof components due to normal wear and aging. Failureto adhere to proper maintenance intervals andprocedures may result in diminished performance ofthe product and/or accelerated wear of components.

Use mileage, fuel consumption, service hours, orcalendar time, WHICH EVER OCCURS FIRST,in order to determine the maintenance intervals.Products that operate in severe operating conditionsmay require more frequent maintenance.

Note: Before each consecutive interval is performed,all maintenance from the previous interval must beperformed.

When Required

Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Engine Air Cleaner Element - Replace ................. 91Fuel Metering Valve - Check ............................... 100Generator - Dry ................................................... 102Generator Bearing - Lubricate ............................ 105Generator Set - Test ........................................... 109Insulation - Test .................................................... 118Overhaul Considerations .................................... 127Space Heater - Check ........................................ 129Stator Winding Temperature - Measure/Record .. 131Throttle Control Valve - Check ............................ 131

Daily

Air Tank Moisture and Sediment - Drain ............... 81Cooling System Coolant Level - Check ................ 86Engine Oil Level - Check ...................................... 96Fuel System Fuel Filter Differential Pressure -Check ................................................................ 100Fumes Disposal Filter Differential Pressure -Check ................................................................ 101Generator Load - Check ..................................... 108Jacket Water Heater - Check .............................. 121Power Factor - Check ......................................... 128Turbocharger - Inspect ........................................ 131Voltage and Frequency - Check ......................... 135Walk-Around Inspection ...................................... 135

Initial 250 Service Hours

Crankcase Blowby - Measure/Record .................. 88Cylinder Pressure - Measure/Record ................... 90

Every 250 Service Hours

Battery Electrolyte Level - Check .......................... 81Cooling System Coolant Sample (Level 1) -Obtain ................................................................. 86Cooling System Supplemental Coolant Additive(SCA) - Test/Add ................................................. 87Engine Oil Sample - Obtain .................................. 97Fumes Disposal Filter - Drain ............................. 101


Aftercooler Condensation - Drain ......................... 81Alternator - Inspect ............................................... 81Belts - Inspect/Adjust/Replace .............................. 82Crankcase Pressure - Measure ............................ 89Crankshaft Vibration Damper - Inspect ................. 89Engine Crankcase Breather - Clean ..................... 92Engine Oil - Change ............................................. 93Engine Oil Filter - Change .................................... 95Engine Speed/Timing Sensor - Clean/Inspect ...... 98Engine Valve Lash and Bridge - Adjust ................ 99Flexible Coupling - Inspect ................................. 100Gas Pressure Regulator Condensation - Drain .. 102Hoses and Clamps - Inspect/Replace ................. 110Inlet Air System - Inspect ..................................... 117Radiator - Clean .................................................. 128Valve Stem Projection - Measure/Record ........... 133Water Pump - Inspect ......................................... 136


Carburetor Air/Fuel Ratio - Check/Adjust ............. 83Compressor Bypass - Check ................................ 83Generator - Inspect ............................................. 104Generator Set Vibration - Inspect ....................... 109Stator Lead - Check ............................................ 131

Every Year

Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87

74 SEBU7681-14Maintenance SectionMaintenance Interval Schedule


Ignition System Spark Plugs - Replace ............... 114


Crankcase Blowby - Measure/Record .................. 88Cylinder Pressure - Measure/Record ................... 90Engine Mounts - Check ........................................ 93Engine Protective Devices - Check ...................... 97Ignition System Timing - Check/Adjust ................ 117Starting Motor - Inspect ...................................... 130


Fumes Disposal Filter Element - Replace .......... 101Oil Temperature Regulators - Replace ............... 121Rotating Rectifier - Check ................................... 129Varistor - Test ...................................................... 134Water Temperature Regulator - Replace ............ 137Winding - Test ..................................................... 138

Between 10 000 and 20 000 Service Hours

Overhaul (Top End) ............................................. 124


Crankshaft Vibration Damper - Inspect ................. 90Overhaul (In-Frame) ........................................... 121

Every 24 000 Service Hours or 3 Years

Cooling System Coolant (NGEC) - Change .......... 83


Crankshaft Vibration Damper - Inspect ................. 90Overhaul (Major) ................................................. 122



i03675800

Maintenance Interval Schedule(Standby)SMCS Code: 1000; 4450; 7500

S/N: GZA1-Up

S/N: GSB1-Up

S/N: GZB1-Up

S/N: TJB1-Up

S/N: GZC1-Up

S/N: TJC1-Up

S/N: GZG1-Up

S/N: GZH1-Up

S/N: GZL1-Up

S/N: HAL1-Up

S/N: GZM1-Up

S/N: GZN1-Up

S/N: B9P1-Up

S/N: RLP1-Up

S/N: SSR1-Up

S/N: GAS1-Up

S/N: NGS1-Up

S/N: CWW1-Up

S/N: GTX1-Up

S/N: CWY1-Up

S/N: SLY1-Up

S/N: SXY1-Up

S/N: GZZ1-Up



Use fuel consumption, service hours, or calendartime, WHICH EVER OCCURS FIRST, in order todetermine the maintenance intervals. Products thatoperate in severe operating conditions may requiremore frequent maintenance.


When Required

Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Engine Air Cleaner Element - Replace ................. 91Fuel Metering Valve - Check ............................... 100Generator - Dry ................................................... 102Generator Bearing - Lubricate ............................ 105Throttle Control Valve - Check ............................ 131

Daily

Engine Oil Level - Check ...................................... 96Fumes Disposal Filter Differential Pressure -Check ................................................................ 101Turbocharger - Inspect ........................................ 131

Every Week

Air Tank Moisture and Sediment - Drain ............... 81Battery Electrolyte Level - Check .......................... 81Cooling System Coolant Level - Check ................ 86Fuel System Fuel Filter Differential Pressure -Check ................................................................ 100Generator Load - Check ..................................... 108Jacket Water Heater - Check .............................. 121Power Factor - Check ......................................... 128Space Heater - Check ........................................ 129Walk-Around Inspection ...................................... 135


Cooling System Coolant Sample (Level 1) -Obtain ................................................................. 86Cooling System Supplemental Coolant Additive(SCA) - Test/Add ................................................. 87


Flexible Coupling - Inspect ................................. 100Valve Stem Projection - Measure/Record ........... 133

Every 1000 Service Hours or 6 Months

Engine Oil - Change ............................................. 93

Every 1000 Service Hours or 1 Year

Engine Oil Filter - Change .................................... 95


Carburetor Air/Fuel Ratio - Check/Adjust ............. 83


Compressor Bypass - Check ................................ 83Generator - Inspect ............................................. 104

Every Year

Aftercooler Condensation - Drain ......................... 81Alternator - Inspect ............................................... 81Belts - Inspect/Adjust/Replace .............................. 82Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Crankcase Blowby - Measure/Record .................. 88Crankshaft Vibration Damper - Inspect ................. 89Cylinder Pressure - Measure/Record ................... 90Engine Crankcase Breather - Clean ..................... 92Engine Mounts - Check ........................................ 93Engine Oil Sample - Obtain .................................. 97Engine Protective Devices - Check ...................... 97Engine Speed/Timing Sensor - Clean/Inspect ...... 98Engine Valve Lash and Bridge - Adjust ................ 99Gas Pressure Regulator Condensation - Drain .. 102Generator Set Vibration - Inspect ....................... 109Hoses and Clamps - Inspect/Replace ................. 110Inlet Air System - Inspect ..................................... 117Insulation - Test .................................................... 118Radiator - Clean .................................................. 128Starting Motor - Inspect ...................................... 130Stator Lead - Check ............................................ 131



Every 3 Years

Cooling System Coolant (NGEC) - Change .......... 83Rotating Rectifier - Check ................................... 129


Ignition System Timing - Check/Adjust ................ 117


Oil Temperature Regulators - Replace ............... 121Varistor - Test ...................................................... 134Winding - Test ..................................................... 138



i03675795

Maintenance Interval Schedule(Standard for G3500CGenerator Sets)SMCS Code: 1000; 4450; 7500

S/N: GZA1-Up

S/N: GSB1-Up

S/N: GZB1-Up

S/N: TJB1-Up

S/N: GZC1-Up

S/N: TJC1-Up

S/N: GZL1-Up

S/N: GZM1-Up

S/N: GZN1-Up

S/N: B9P1-Up

S/N: RLP1-Up

S/N: CWW1-Up

S/N: CWY1-Up

S/N: GZZ1-Up





When Required

Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Engine Air Cleaner Element - Replace ................. 91Fuel Metering Valve - Check ............................... 100

Generator - Dry ................................................... 102Generator Bearing - Lubricate ............................ 105Generator Set - Test ........................................... 109Insulation - Test .................................................... 118Overhaul Considerations .................................... 127Space Heater - Check ........................................ 129Stator Winding Temperature - Measure/Record .. 131Throttle Control Valve - Check ............................ 131

Daily

Air Tank Moisture and Sediment - Drain ............... 81Cooling System Coolant Level - Check ................ 86Engine Oil Level - Check ...................................... 96Fuel System Fuel Filter Differential Pressure -Check ................................................................ 100Fumes Disposal Filter Differential Pressure -Check ................................................................ 101Generator Load - Check ..................................... 108Jacket Water Heater - Check .............................. 121Power Factor - Check ......................................... 128Turbocharger - Inspect ........................................ 131Voltage and Frequency - Check ......................... 135Walk-Around Inspection ...................................... 135






Aftercooler Condensation - Drain ......................... 81Alternator - Inspect ............................................... 81Belts - Inspect/Adjust/Replace .............................. 82Crankcase Pressure - Measure ............................ 89Crankshaft Vibration Damper - Inspect ................. 89Engine Crankcase Breather - Clean ..................... 92Engine Oil - Change ............................................. 93Engine Oil Filter - Change .................................... 95Engine Speed/Timing Sensor - Clean/Inspect ...... 98Engine Valve Lash and Bridge - Adjust ................ 99Flexible Coupling - Inspect ................................. 100Gas Pressure Regulator Condensation - Drain .. 102Hoses and Clamps - Inspect/Replace ................. 110Inlet Air System - Inspect ..................................... 117Radiator - Clean .................................................. 128Valve Stem Projection - Measure/Record ........... 133Water Pump - Inspect ......................................... 136



Carburetor Air/Fuel Ratio - Check/Adjust ............. 83Compressor Bypass - Check ................................ 83Generator - Inspect ............................................. 104Generator Set Vibration - Inspect ....................... 109Stator Lead - Check ............................................ 131

Every Year









Crankshaft Vibration Damper - Inspect ................. 90Overhaul (In-Frame) ........................................... 121Overhaul (Top End) ............................................. 124







i03675805

Maintenance Interval Schedule(Landfill)SMCS Code: 1000; 4450; 7500

S/N: MAD1-Up

S/N: GZJ1-Up

S/N: GZK1-Up

S/N: LGS1-Up

S/N: HAT1-Up





When Required

Cooling System Coolant Sample (Level 2) -Obtain ................................................................. 87Engine Air Cleaner Element - Replace ................. 91Engine Oil - Change ............................................. 93Fuel Metering Valve - Check ............................... 100Generator - Dry ................................................... 102Generator Bearing - Lubricate ............................ 105Generator Set - Test ........................................... 109Insulation - Test .................................................... 118Overhaul Considerations .................................... 127Space Heater - Check ........................................ 129Stator Winding Temperature - Measure/Record .. 131Throttle Control Valve - Check ............................ 131

Daily

Cooling System Coolant Level - Check ................ 86Engine Oil Level - Check ...................................... 96Fuel System Fuel Filter Differential Pressure -Check ................................................................ 100

Fumes Disposal Filter Differential Pressure -Check ................................................................ 101Generator Load - Check ..................................... 108Power Factor - Check ......................................... 128Turbocharger - Inspect ........................................ 131Voltage and Frequency - Check ......................... 135Walk-Around Inspection ...................................... 135






Aftercooler Condensation - Drain ......................... 81Alternator - Inspect ............................................... 81Belts - Inspect/Adjust/Replace .............................. 82Crankcase Pressure - Measure ............................ 89Crankshaft Vibration Damper - Inspect ................. 89Engine Crankcase Breather - Clean ..................... 92Engine Oil Filter - Change .................................... 95Engine Speed/Timing Sensor - Clean/Inspect ...... 98Engine Valve Lash and Bridge - Adjust ................ 99Flexible Coupling - Inspect ................................. 100Gas Pressure Regulator Condensation - Drain .. 102Hoses and Clamps - Inspect/Replace ................. 110Inlet Air System - Inspect ..................................... 117Radiator - Clean .................................................. 128Valve Stem Projection - Measure/Record ........... 133Water Pump - Inspect ......................................... 136


Compressor Bypass - Check ................................ 83Generator - Inspect ............................................. 104Generator Set Vibration - Inspect ....................... 109Ignition System Spark Plugs - Inspect/Replace ... 111Stator Lead - Check ............................................ 131

Every Year





Between 7500 and 8000 Service Hours

Overhaul (Top End) ............................................. 124




Crankshaft Vibration Damper - Inspect ................. 90Overhaul (In-Frame) ........................................... 121






Aftercooler Condensation - Drain

i01721862

Aftercooler Condensation -DrainSMCS Code: 1063

The air/fuel mixture that is compressed and warmedby the turbocharger compressor is directed throughthe aftercooler core. The air/fuel mixture is cooled inthe aftercooler.

Condensation can form in the housing of theaftercooler. A drain plug is provided for draining thecondensation.

Note: An automatic drain is available for use with32° C (90 °F) separate circuit aftercoolers. Consultyour Caterpillar dealer for details.


Remove the drain plugs (1) from the ends of theplenum. Drain the moisture into a suitable container.Reinstall the plugs.

i00351324

Air Tank Moisture andSediment - DrainSMCS Code: 1466-543-M&S

Moisture and sediment in the air starting system cancause the following conditions:

• Freezing

• Corrosion of internal parts

• Malfunction of the air starting system

When opening the drain valve, wear protectivegloves, a protective face shield, protective cloth-ing, and protective shoes. Pressurized air couldcause debris to be blown and result in personalinjury.

1. Open the drain valve that is on the bottom of theair tank. Allow the moisture and sediment to drain.

2. Close the drain valve.

i02084374

Alternator - InspectSMCS Code: 1405-040

Inspect the alternator for the following conditions:

• Proper connections

• Clean ports for cooling airflow

• Proper charging of the battery

Observe the ammeter during engine operation inorder to ensure proper battery performance and/orproper performance of the electrical system.

Make repairs, if necessary. See the Service Manualfor service procedures. Consult your Caterpillardealer for assistance.

i02601752

Battery Electrolyte Level -CheckSMCS Code: 1401-535-FLV

When the engine is not run for long periods of time orwhen the engine is run for short periods, the batteriesmay not fully recharge. Ensure a full charge in orderto help prevent the battery from freezing.

All lead-acid batteries contain sulfuric acid whichcan burn the skin and clothing. Always wear a faceshield and protective clothing when working on ornear batteries.

1. Remove the filler caps. Maintain the electrolytelevel to the “FULL” mark on the battery.

82 SEBU7681-14Maintenance SectionBelts - Inspect/Adjust/Replace

If the addition of water is necessary, use distilledwater. If distilled water is not available use cleanwater that is low in minerals. Do not use artificiallysoftened water.

2. Check the condition of the electrolyte with the245-5829 Coolant Battery Tester Refractometer.

3. Keep the batteries clean.

Clean the battery case with one of the followingcleaning solutions:

• A mixture of 0.1 kg (0.2 lb) of baking soda and1 L (1 qt) of clean water

• A mixture of 0.1 L (0.11 qt) of ammonia and 1 L(1 qt) of clean water

Thoroughly rinse the battery case with clean water.

Use a fine grade of sandpaper to clean theterminals and the cable clamps. Clean the itemsuntil the surfaces are bright or shiny. DO NOTremove material excessively. Excessive removalof material can cause the clamps to not fit properly.Coat the clamps and the terminals with 5N-5561Silicone Lubricant, petroleum jelly or MPGM.

i02667833

Belts - Inspect/Adjust/ReplaceSMCS Code: 1357-025; 1357-040; 1357-510

InspectionInspect the alternator belt and the fan drive belts forwear and for cracking. Replace the belts if the beltsare not in good condition.

Check the belt tension according to the information inthe Service Manual, “Specifications”.

Slippage of loose belts can reduce the efficiencyof the driven components. Vibration of loose beltscan cause unnecessary wear on the followingcomponents:

• Belts

• Pulleys

• Bearings

If the belts are too tight, unnecessary stress is placedon the components. This reduces the service life ofthe components.

Adjusting the Alternator Belt

g01092641Illustration 45Typical alternator

(1) Mounting bolt(2) Adjusting nuts(3) Mounting bolt

1. Remove the drive belt guard.

2. Loosen mounting bolt (1), adjusting nuts (2) andmounting bolt (3).

3. Turn adjusting nuts (2) in order to increase ordecrease the drive belt tension.

4. Tighten adjusting nuts (2). Tighten mounting bolt(3). Tighten mounting bolt (1). For the propertorque, see the Service Manual, “Specifications”module.

5. Reinstall the drive belt guard.

If new drive belts are installed, check the drive belttension again after 30 minutes of engine operation atthe rated rpm.

Adjusting the Fan Drive Belt1. Loosen the mounting bolt for the pulley.

2. Loosen the adjusting nut for the pulley.

3. Move the pulley in order to adjust the belt tension.

4. Tighten the adjusting nut to the proper torque.

5. Tighten the mounting bolt to the proper torque.


Carburetor Air/Fuel Ratio - Check/Adjust

For the proper torque specifications, refer to theService Manual, “Specifications” module.

ReplacementFor applications that require multiple drive belts,replace the drive belts in matched sets. Replacingone drive belt of a matched set will cause the newdrive belt to carry more load because the older drivebelts are stretched. The additional load on the newdrive belt could cause the new drive belt to fail.

i02904927

Carburetor Air/Fuel Ratio -Check/AdjustSMCS Code: 1266-535; 1266

An engine failure may occur if the air/fuel ratio isnot appropriate for the fuel and for the operatingconditions. The service life of the turbocharger, of thevalves, and of the other components may be reduced.

Refer to the Systems Operation, Testing andAdjusting for the correct procedure.

i02896718

Compressor Bypass - CheckSMCS Code: 1050-535


Hydraulically operated valve

Check for leaks. If necessary, remove the actuatoraccording to the instructions in the Service Manual,“Disassembly and Assembly” manual. Inspect thethroat for wear marks. Check for free movement ofthe butterfly valve. If necessary, replace the valve.

Inspect the gaskets for wear or damage. Ifnecessary, replace the gaskets. Reinstall the actuatoraccording to the instructions in the Service Manual,“Disassembly and Assembly” manual.

Inspect the coupling for the compressor bypass forwear and play. If necessary, replace the coupling.Excessive wear in the coupling can cause low poweror instability in the engine.

i02903700

Cooling System Coolant(NGEC) - ChangeSMCS Code: 1350-044

Clean the cooling system before the recommendedmaintenance interval if the following conditions exist:

• The engine overheats frequently.

• Foaming is observed.

• The oil has entered the cooling system and thecoolant is contaminated.

• Coolant analysis indicates that the coolant hasbroken down.

Draining the Cooling System

NOTICECare must be taken to ensure that fluids are containedduring performance of inspection, maintenance, test-ing, adjusting and repair of the product. Be prepared tocollect the fluid with suitable containers before open-ing any compartment or disassembling any compo-nent containing fluids.

Refer to Special Publication, NENG2500, “CaterpillarDealer Service Tool Catalog” for tools and suppliessuitable to collect and contain fluids on Caterpillarproducts.

Dispose of all fluids according to local regulations andmandates.

Stop the engine and allow the engine to cool. Ensurethat the engine will not start when the cooling systemis drained.

For information regarding the disposal and therecycling of used coolant, consult your Caterpillardealer or consult Caterpillar Dealer Service ToolsGroup:

Outside Illinois: 1-800-542-TOOLInside Illinois: 1-800-541-TOOLCanada: 1-800-523-TOOL

84 SEBU7681-14Maintenance SectionCooling System Coolant (NGEC) - Change

NOTICEDispose of used engine coolant properly or recycle.Various methods have been proposed to reclaim usedcoolant for reuse in engine cooling systems. The fulldistillation procedure is the only method acceptable byCaterpillar to reclaim the used coolant.

Draining the Jacket Water

1. Loosen the cooling system filler cap slowly inorder to relieve any pressure. Remove the coolingsystem filler cap.

g01445608Illustration 47Locations of the vent and drain plugs

(1) Coolant outlet(2) Aftercooler drain plug(3) Oil cooler drain plug(4) Engine block drain plug(5) Drain plug for the adapter

2. Remove the vent plug from coolant outlet (1).Open drain (2). Remove drain plugs (3), (4), and(5).

Draining the Separate Circuit


1. Remove vent plugs (6).

2. Open coolant drain valve (7).

Clean the Cooling System

NOTICEUse of commercially available cooling system clean-ers may cause damage to cooling system compo-nents. Use only cooling system cleaners that are ap-proved for Caterpillar engines.

1. After the cooling system has been drained, flushthe cooling system with clean water in order toremove any debris.

2. Close the cooling system drain valves. Clean thedrain plugs and install the drain plugs.

NOTICEFill the cooling system no faster than 19 L (5 US gal)per minute to avoid air locks.

NOTICEIf the aftercooler circuit has been drained, the ventplug must be opened to allow the aftercooler to fillproperly. Failure to do this will cause an air lock re-sulting in engine damage.

3. When the separate circuit is filled, be sure toremove the vent plug.

4. Fill the cooling system with a mixture of cleanwater and Caterpillar Fast Acting Cooling SystemCleaner. Add 0.5 L (1 pint) of cleaner per 15 L(4 US gal) of the cooling system capacity. Installthe cooling system filler cap. Install vent plugs (1).


Cooling System Coolant (NGEC) - Change

5. Start the engine. Operate the engine for aminimum of 30 minutes with a coolant temperatureof at least 82 °C (180 °F).

6. Stop the engine and allow the engine to cool. Forthe jacket water and the separate circuit, loosenthe cooling system filler cap slowly in order torelieve any pressure. Remove the cooling systemfiller cap. Open the cooling system drain valvesand remove the drain plugs. Remove the ventplugs. Allow the cleaning solution to drain.

NOTICEImproper or incomplete rinsing of the cooling systemcan result in damage to copper and other metal com-ponents.

To avoid damage to the cooling system, make sureto completely flush the cooling system with clear wa-ter. Continue to flush the system until all signs of thecleaning agent are gone.

7. Flush the cooling system with clean water untilthe water that drains is clean. Close the coolingsystem drain valves. Clean the drain plugs andinstall the drain plugs.

Cleaning a Cooling System thathas Heavy Deposits or PluggingNote: For the following procedure to be effective,there must be an active flow through the coolingsystem components.

1. After the cooling system has been drained, flushthe cooling system with clean water in order toremove any debris.

2. Close the cooling system drain valves. Clean thedrain plugs and install the drain plugs.

3. Remove the vent plugs.

4. Fill the cooling system with a mixture of cleanwater and Caterpillar Fast Acting Cooling SystemCleaner. Add 0.5 L (1 pint) of cleaner per3.8 to 7.6 L (1 to 2 US gal) of the cooling systemcapacity. Install the cooling system filler cap.Install the vent plugs.

5. Start the engine. Operate the engine for aminimum of 90 minutes with a coolant temperatureof at least 82 °C (180 °F).

6. Stop the engine and allow the engine to cool.Loosen the cooling system filler cap slowly inorder to relieve any pressure. Remove the coolingsystem filler cap. Open the cooling system drainvalves and remove the drain plugs. Remove thevent plugs. Allow the cleaning solution to drain.

NOTICEImproper or incomplete rinsing of the cooling systemcan result in damage to copper and other metal com-ponents.

To avoid damage to the cooling system, make sureto completely flush the cooling system with clear wa-ter. Continue to flush the system until all signs of thecleaning agent are gone.

7. Flush the cooling system with clean water untilthe water that drains is clean. Close the coolingsystem drain valves. Clean the drain plugs andinstall the drain plugs.

Fill the Cooling System

NOTICEIt is recommended that the cooling system is filledfrom the bottom with the cap removed from the ex-pansion tank.

NOTICEFill the cooling system no faster than 19 L (5 US gal)per minute to avoid air locks.

Note: For information about the proper coolant touse, and for the capacity of the cooling system, referto this Operation and Maintenance Manual, “RefillCapacities and Recommendations” (MaintenanceSection).

1. Remove the vent plugs.

2. Fill the cooling system with coolant or antifreeze.Install the vent plugs. Do not install the coolingsystem filler cap yet.

3. Start the engine. Operate the engine in order topurge the air from the cavities of the engine block.Allow the coolant to warm and allow the coolantlevel to stabilize. Stop the engine.

4. Check the coolant level. Maintain the coolant tothe proper level on the sight gauge (if equipped).If the machine is not equipped with a sight gauge,maintain the coolant within 13 mm (0.5 inch)below the bottom of the filler pipe.

5. Clean the cooling system filler cap. Inspectthe gaskets of the cooling system filler cap. Ifthe gaskets of the cooling system filler cap aredamaged, discard the old cooling system filler capand install a new cooling system filler cap.

6. Start the engine. Inspect the cooling system forleaks and for proper operating temperature.

86 SEBU7681-14Maintenance SectionCooling System Coolant Level - Check

i02017615

Cooling System Coolant Level- CheckSMCS Code: 1350-535-FLV

Climbing equipment may be required to accessthis service point. Refer to the Operation andMaintenance Manual, “Mounting and Dismount-ing” topic for safety information.

NOTICEOverfilling the overflow tank (if equipped) will result indamage to the cooling system.

If the cooling system has an overflow tank, maintainthe coolant level in the tank below 1/2 full in order toavoid damage to the cooling system.

g00760290Illustration 49Normal position of the coolant in the sight gauge during ratedoperation

Observe the coolant level in the sight gauge (ifequipped). When the engine is running at normaloperating temperature, the coolant should be in theupper half of the sight gauge. If the coolant level islow, add the proper coolant mixture.

Add CoolantNote: For the proper coolant mixture to use, seethis Operation and Maintenance Manual, “RefillCapacities and Recommendations” topic.

1. Stop the engine. Allow the engine to cool.

2. Remove the cooling system filler cap slowly inorder to relieve any pressure. Pour the propercoolant mixture into the filler pipe.

g00103639Illustration 50Filler cap gaskets

3. Clean the cooling system filler cap. Inspect thegaskets of the cooling system filler cap. If thegaskets are damaged, replace the old coolingsystem filler cap with a new cooling system fillercap. Install the cooling system filler cap.

4. Start the engine. Inspect the cooling system forleaks.

i02064894

Cooling System CoolantSample (Level 1) - ObtainSMCS Code: 1350-008; 1395-008; 1395-554; 7542

NOTICEAlways use a designated pump for oil sampling, anduse a separate designated pump for coolant sampling.Using the same pump for both types of samples maycontaminate the samples that are being drawn. Thiscontaminate may cause a false analysis and an incor-rect interpretation that could lead to concerns by bothdealers and customers.

For conventional heavy-duty coolant/antifreeze,check the concentration of supplemental coolantadditive (SCA) regularly. The concentration of SCAcan be checked with an S·O·S coolant analysis(Level 1).

Obtain the sample of the coolant as close as possibleto the recommended sampling interval. In orderto receive the full effect of S·O·S analysis, youmust establish a consistent trend of data. In orderto establish a pertinent history of data, performconsistent samplings that are evenly spaced.Supplies for collecting samples can be obtained fromyour Caterpillar dealer.

Use the following guidelines for proper sampling ofthe coolant:


Cooling System Coolant Sample (Level 2) - Obtain

• Never collect samples from expansion bottles.

• Never collect samples from the drain for a system.

• Keep the unused sampling bottles stored in plasticbags.

• Keep the lids on empty sampling bottles until youare ready to collect the sample.

• Complete the information on the label for thesampling bottle before you begin to take thesamples.

• Obtain coolant samples directly from the coolantsample port. You should not obtain the samplesfrom any other location.

• In order to avoid contamination, immediately placethe sample in the tube that is provided for mailing.

Submit the sample for Level 1 analysis.

Note: Level 1 results may indicate a need forLevel 2 Analysis.

For additional information about coolant analysis,see the Special Publication, SEBU6400, “CaterpillarGas Engine Lubricant, Fuel and CoolantRecommendations” or consult your Caterpillar dealer.

i02168823

Cooling System CoolantSample (Level 2) - ObtainSMCS Code: 1350-008; 1395-008; 1395-554; 7542


Obtain the sample of the coolant as close as possibleto the recommended sampling interval. Suppliesfor collecting samples can be obtained from yourCaterpillar dealer.

Refer to this Operation and Maintenance Manual,“Cooling System Coolant Sample (Level 1) - Obtain”(Maintenance Section) for the guidelines for propersampling of the coolant.

Submit the sample for Level 2 analysis.

For additional information about coolant analysis,see the Special Publication, SEBU6400, “CaterpillarGas Engine Lubricant, Fuel, and CoolantRecommendations” or consult your Caterpillar dealer.

i02017557

Cooling System SupplementalCoolant Additive (SCA) -Test/AddSMCS Code: 1352-045; 1395-081

Cooling system coolant additive contains alkali.To help prevent personal injury, avoid contact withthe skin and eyes. Do not drink cooling systemcoolant additive.

Note: Caterpillar recommends an S·O·S coolantanalysis (Level 1).

Test the Concentration of the SCA

Coolant/Antifreeze and SCA

NOTICEDo not exceed the recommended six percent supple-mental coolant additive concentration.

Test the concentration of the SCA with the 8T-5296Coolant Conditioner Test Kit. Follow the instructionsthat are provided in the kit.

Water and SCA

NOTICEDo not exceed the recommended eight percent sup-plemental coolant additive concentration.

Test the concentration of the SCA with the 8T-5296Coolant Conditioner Test Kit. Use the instructionsthat follow:

1. Fill the syringe to the “1.0 ml” mark with thecoolant.

2. Dispense the 1.0 mL coolant sample from thesyringe into the empty mixing bottle.

3. Add tap water to the mixing bottle in order to bringthe level up to the “10 ml” mark. Place the cap onthe bottle and shake the bottle.

88 SEBU7681-14Maintenance SectionCrankcase Blowby - Measure/Record

4. Add 2 to 3 drops of the “NITRITE INDICATORSOLUTION B” to the mixing bottle. Move the bottlein a circular motion in order to mix the solution.

5. Add 1 drop of “NITRITE TEST SOLUTION A” tothe mixing bottle. Move the bottle in a circularmotion in order to mix the solution.

6. Repeat 5 until the solution changes color from redto light gray, green, or blue. Record the number ofdrops of “NITRITE TEST SOLUTION A” that wererequired to cause the color change.

7. Use Table 16 to interpret the results.

Table 16

Number ofDrops

Concentrationof SCA

MaintenanceRequired

Less than 25 Less than therecommendedconcentration ofSCA

Add SCA.Retest thecoolant.

25 to 30 Therecommendedconcentration ofSCA

None

More than 30 More than therecommendedconcentration ofSCA

Remove thecoolant.Replace withwater onlyRetest thecoolant.

Add the SCA, If Necessary

Pressurized System: Hot coolant can cause seri-ous burns. To open the cooling system filler cap,stop the engine and wait until the cooling systemcomponents are cool. Loosen the cooling systempressure cap slowly in order to relieve the pres-sure.

1. Remove the cooling system filler cap slowly.

Note: Always dispose of fluids according to localregulations.

2. If necessary, drain some coolant in order to allowspace for the addition of the SCA.

NOTICEExcessive supplemental coolant additive concentra-tion can form deposits on the higher temperature sur-faces of the cooling system, reducing the engine'sheat transfer characteristics. Reduced heat transfercould cause cracking of the cylinder head and otherhigh temperature components.

Excessive supplemental coolant additive concentra-tion could also result in blockage of the heat exchang-er, overheating, and/or accelerated wear of the waterpump seal.

Do not exceed the recommended amount of supple-mental coolant additive concentration.

3. Add the proper amount of SCA. The concentrationof the SCA depends on the type of coolant thatis used. To determine the proper amount, seethis Operation and Maintenance Manual, “RefillCapacities and Recommendations” topic.

4. Clean the cooling system filler cap. Install thecooling system filler cap.

i01935045

Crankcase Blowby -Measure/RecordSMCS Code: 1317

Measure the crankcase blowby of new engines.Record the data. Continue to periodically measurethe blowby. Comparing the recorded data to the newdata provides information about the condition of theengines.

Note: Crankcase blowby is one of the three factorsthat help to determine the in-frame overhaul interval.For more information, see this Operation andMaintenance manual, “Overhaul (In-Frame)” topic.

After a new engine is used for a short time, theblowby can decrease as the piston rings are seated.The blowby will gradually increase as the followingcomponents show wear:

• Piston rings

• Cylinder liners

Note: A problem with the piston rings causes theoil to deteriorate rapidly. Information regarding thecondition of the piston rings can be obtained fromthe measurement of the blowby and the results ofoil analysis.


Crankcase Pressure - Measure

The blowby of a worn engine may exceed the blowbyof a new engine by two times or more.

A sudden increase in blowby could indicate a brokenpiston ring. The following conditions are otherpotential sources of blowby:

• Worn valve guides

• A turbocharger seal that leaks

A rebuilt engine can have a high blowby due to thefollowing factors:

• The piston rings are not seated properly.

• Worn parts such as valve guides were not replaced.

Excessive blowby may indicate the need for anoverhaul. By keeping a record of the results, agradual increase in the amount of the blowby will benoted until the amount has become excessive.

To measure the blowby, use the 1U-8860 LargeEngine Blowby Pickup Group with the 8T-2701Blowby Indicator. For instructions, see SpecialInstruction, SEHS8984, “Using the 1U-8860Large Engine Blowby Pickup Group” and SpecialInstruction, SEHS8712, “Using the 8T-2700Blowby/Air Flow Indicator”.

For assistance, consult your Caterpillar dealer.

i01601829

Crankcase Pressure - Measure(Engines with Fumes DisposalFilters)SMCS Code: 1074

Measure the crankcase pressure during normaloperation.

With a fumes disposal filter that is properly installed,the crankcase pressure will be within 0.25 kPa(1 inch of H2O) of the atmospheric pressure.

i02896726

Crankshaft Vibration Damper- InspectSMCS Code: 1205-040

The crankshaft vibration damper limits the torsionalvibration of the crankshaft. The visconic damper hasa weight that is located inside a fluid filled case.

Damage to the crankshaft vibration damper or failureof the damper can increase torsional vibrations. Thiscan result in damage to the crankshaft and to otherengine components. A deteriorating damper cancause excessive gear train noise at variable pointsin the speed range.

A damper that is hot is typically due to excessivetorsional vibration. A hot damper can also be due tothe operating environment. See the Service Manual,“Application and Installation Guideline”. Monitor thetemperature of the damper during operation.

The 8T-2821 Temperature Indicator or the 8T-2822Temperature Indicator are recommended formonitoring the temperature of the damper. Evenlyspace four of the adhesive indicators around theouter diameter of the damper.

Note: If you use an infrared thermometer to monitorthe temperature of the damper, use the thermometerduring operation with similar loads and speeds. Keepa record of the data. If the temperature begins to rise,reduce the interval for inspecting the damper andinstall temperature indicator strips for more accuratereadings.

If the temperature of the damper reaches 90 °C(194 °F), reduce the interval for inspecting thedamper. If the temperature of the damper reaches100 °C (212 °F), consult your Caterpillar dealer.

Inspect the damper for evidence of dents, cracks,and leaks of the fluid.

If a fluid leak is found, repair the damper orreplace the damper. The fluid in the damper issilicone. Silicone has the following characteristics:transparent, viscous, smooth, and sticky.

Inspect the damper and repair or replace the damperfor any of the following reasons.

• The damper is dented, cracked, or leaking.

• The paint on the damper is discolored from heat.

• The engine has had a failure because of a brokencrankshaft.

• An analysis of the oil has revealed that the frontbearing of the crankshaft is badly worn.

• There is a large amount of gear train wear that isnot caused by a lack of oil.

Removal and InstallationRefer to the Service Manual, “Disassembly andAssembly” or consult your Caterpillar dealer forinformation about damper replacement.

90 SEBU7681-14Maintenance SectionCrankshaft Vibration Damper - Inspect

i03529602

Crankshaft Vibration Damper- Inspect(1500 RPM G3520 engines(if equipped with an oil feddamper))SMCS Code: 1205-040

S/N: GZB1-Up

S/N: GZH1-Up

S/N: HAL1-Up

S/N: GZN1-Up

S/N: RLP1-Up

S/N: LGS1-Up

There are two service intervals for the crankshaftvibration damper, a short interval, and a long interval.The following maintenance procedure must becompleted at each service interval:

1. Remove the damper.

2. Separate the inner member of the damper fromthe outer member of the damper.

Note: Do not disassemble the damper springassembly.

3. Clean all parts of the damper. Pay special attentionto the oil supply and venting holes.

4. Replace all accessible rubber seal rings.

5. Replace all disc springs from bolts that have beenremoved.

6. Replace all lockwashers on the bolts that havebeen removed.

7. Check the service literature that is provided by theOEM of the damper for permissible wear.

Parts that are exposed to wear may need to berepaired or exchanged.

At each long service interval, the following stepsmust also be completed:

1. Disassemble the outer member of the damper.

2. Service the spring packs. If necessary, replace thespring packs. Check permissible wear accordingto the service literature that is provided by theOEM of the damper.

3. Service the inner star. If necessary, replace theinner star. Check permissible wear according tothe service literature that is provided by the OEMof the damper.

Refer to Service Manual, RENR5980, “Disassemblyand Assembly” for proper procedures.

i01664707

Cylinder Pressure -Measure/RecordSMCS Code: 1223-082-CC; 1223; 7450-082

Measure the cylinder pressure of new engines.Record the data. Continue to periodically measurethe cylinder pressure. Comparing the recorded datato the new data provides information about thecondition of the engine.

Cylinder pressure can be measured during inspectionof the spark plugs. Use the following guidelines forchecking the cylinder pressure:

• Remove all of the spark plugs.

• Fully open the throttle plate.

• Minimize the cranking time to 3 or 4 revolutions.This will enable a maximum consistent crankingspeed for the check. Also, the battery power willbe conserved.

A loss of cylinder pressure or a change of pressurein one or more cylinders may indicate the followingconditions. These conditions may indicate a problemwith lubrication:

• Excessive deposits

• Guttering of valves

• A broken valve

• A piston ring that sticks

• A broken piston ring

• Worn piston rings

• Worn cylinder liners

If the cylinder pressure has risen by one or morecompression ratios, the engine needs a top endoverhaul in order to remove deposits. Failure toremove the deposits will increase the chance fordetonation. Severe guttering of the valves will occur.


Engine Air Cleaner Element - Replace

To measure the cylinder pressure, use the 193-5859Cylinder Pressure Gauge Gp. Follow the procedurein the Special Instruction, NEHS0798 that is includedwith the gauge group. Record the pressure foreach cylinder. Use the Operation and MaintenanceManual, “Valve Data Sheet” (Reference MaterialsSection).

Illustration 51 is a graph of typical cylinder pressuresfor engines with different compression ratios.


(Y) Cylinder pressure in kPa(X) Compression ratio(1) Normal range for cylinder pressure

i01935223

Engine Air Cleaner Element -ReplaceSMCS Code: 1051-510; 1054-510

NOTICENever run the engine without an air cleaner elementinstalled. Never run the engine with a damaged aircleaner element. Do not use air cleaner elements withdamaged pleats, gaskets or seals. Dirt entering theengine causes premature wear and damage to enginecomponents. Air cleaner elements help to prevent air-borne debris from entering the air inlet.

NOTICENever service the air cleaner element with the enginerunning since this will allow dirt to enter the engine.

Note: Use of a platform may be necessary to reachthe air cleaner element.

Clean the air cleaner elements or replace the aircleaner elements when the following conditionsoccur:

• Inspect the air cleaner elements before the air filterrestriction reaches 2.5 kPa (10 inches of H2O). Aloss of engine performance may occur when theair filter restriction exceeds this limit.

• The air cleaner elements must be cleaned orreplaced before the air filter restriction exceeds3.75 kPa (15 inches of H2O).

Note: The air filter restriction is measured before theair inlet to the turbocharger compressor.

Servicing the Air Cleaner ElementsNote: If the air cleaner is not manufactured byCaterpillar, follow the instructions that are providedby the OEM of the air cleaner.

If the air cleaner element becomes plugged, the aircan split the material of the air cleaner element.Unfiltered air will drastically accelerate internal enginewear. Your Caterpillar dealer has the proper aircleaner elements for your application. Consult yourCaterpillar dealer for the correct air cleaner element.

• Check the precleaner (if equipped) daily foraccumulation of dirt and debris. Remove any dirtand debris, as needed.

Replace the dirty paper air cleaner elements withclean air cleaner elements. Before installation,thoroughly inspect the air cleaner elements for tearsand/or holes in the filter material. Inspect the gasketor the seal of the air cleaner element for damage.Maintain a supply of suitable air cleaner elementsfor replacement purposes.

1. Remove the air cleaner cover. Remove the aircleaner element.

2. Cover the air inlet to the turbocharger with tapein order to keep dirt out.

3. Clean the inside of the air cleaner cover and bodywith a clean, dry cloth.

92 SEBU7681-14Maintenance SectionEngine Crankcase Breather - Clean

4. Remove the tape for the air inlet to theturbocharger. Install an air cleaner element thatis new or cleaned.

5. Install the air cleaner cover.

Inspecting Air Cleaner Elements


Inspect the clean, dry air cleaner element. Use a60 watt blue light in a dark room or in a similarfacility. Place the blue light in the element. Rotate theelement. Inspect the element for tears and/or holes.Inspect the element for light that may show throughthe filter material. If it is necessary in order to confirmthe result, compare the element to a new elementthat has the same part number.

Do not use an element that has any tears and/orholes in the filter material. Do not use an element withdamaged pleats, gaskets or seals. Discard damagedelements.

Storing Air Cleaner Elements

If an element that passes inspection will not be used,the element can be stored for future use.


Do not use paint, a waterproof cover, or plastic as aprotective covering for storage. Restricted air flowmay result. To protect against dirt and damage, wrapthe elements in Volatile Corrosion Inhibited (VCI)paper.

Place the element into a box for storage. Foridentification, mark the outside of the box.

Store the box in a dry location.

i02895754

Engine Crankcase Breather -CleanSMCS Code: 1317-070

Clean the crankcase breather regularly in orderto prevent excessive crankcase pressure that willdamage the engine's seals.

Perform this maintenance when the engine isstopped.


1. Loosen clamps (1). Slide the clamps off tubes (2).Remove the tubes.

2. Loosen clamps (3). Remove each breatherassembly (4) from the elbow assembly.

3. Remove O-ring seals from the elbow assembly.Inspect the O-ring seals for good condition. Obtainnew O-ring seals, if necessary.

4. Turn the breathers upside-down in order to inspectthe condition of the breather elements.

Note: Do not replace the breathers in theupside-down position. If breathers are not replacedproperly water could enter the crankcase anddamage to the engine could result.


Engine Mounts - Check

Clean the breather elements with clean,nonflammable solvent. If the breather elementsremain contaminated after the cleaning, discardthe breather assemblies and obtain new breatherassemblies. Do not attempt to disassemble thebreather assemblies.

Allow the breather elements to dry beforeinstallation.

Note: Lubricate the bore of the elbow assembly withclean engine oil and install the O-ring seals.

5. Install breather assemblies (4) and tighten clamps(3). Install elbows (2) and clamps (1). Tighten theclamps.

i03214182

Engine Mounts - CheckSMCS Code: 1152-535

g01340704Illustration 55Typical configuration of mounting bolts for a Caterpillar genset(1) Mounting bolts for the engine(2) Mounting bolts for the generator(3) Levelling bolts for the isolators

Misalignment of the engine and the driven equipmentwill cause extensive damage. Excessive vibrationcan lead to misalignment. Excessive vibration of theengine and the driven equipment can be caused bythe following conditions:

• Improper mounting

• Misalignment of driven equipment

• Loose bolts

• Deterioration of the isolators

Ensure that the mounting bolts are tightenedto the proper torque. For standard torques, seeSpecifications, SENR3130, “Torque Specifications”.

Ensure that the isolators are free of oil andcontamination. Inspect the isolators for deterioration.Ensure that the bolts for adjusting the isolator arecorrectly adjusted and secured with the locking nut.Correctly adjusted isolators provide even support forthe engine base. Each isolator should impose nearlyidentical force on the base rail. Each isolator shouldbear the same portion of the weight of the genset.

Replace any isolator that shows deterioration. Formore information, see the literature that is providedby the OEM of the isolators. Also see the Applicationand Installation Guide for the engine. Consult yourCaterpillar dealer for assistance.

i02017618

Engine Oil - ChangeSMCS Code: 1348-044; 1348

Hot oil and components can cause personal in-jury.

Do not allow hot oil or components to contactskin.

NOTICEEnsure that the engine is stopped before performingthis procedure. Attach a DONOTOPERATE tag to thestarting controls.

Do not drain the oil when the engine is cold. As the oilcools, suspended waste particles settle on the bottomof the oil pan. The waste particles are not removedwhen the cold oil is drained. Drain the crankcase withthe oil warm, immediately after the engine is stopped.This draining method allows the waste particlesthat are suspended in the oil to be drained properly.Failure to follow this recommended procedure willallow the waste particles to be recirculated throughthe engine lubrication system with the new oil.

1. After the engine has been operated at normaloperating temperature, STOP the engine.

Note: Drain the oil into a suitable container. Disposeof fluids according to local regulations.

2. Drain the oil by using one of the followingmethods. Use the method that corresponds to theequipment on the engine.

94 SEBU7681-14Maintenance SectionEngine Oil - Change

Note: If a suction device is used in order to removethe oil from the oil pan, ensure that the suction deviceis clean. This will prevent dirt from entering into theoil pan. Be careful not to strike the engine oil suctiontubes or the piston cooling jets.

a. If the engine has an oil drain valve, open thevalve in order to drain the oil. After the oil hasdrained, close the valve.

b. If the engine has a pump for removing dirtyoil, connect a hose to the outlet of the pump.Place the hose in a suitable container. Openthe valve for the drain line. Operate the pumpuntil the crankcase is empty. Close the valve tothe drain line. Disconnect the hose.

c. If the oil drain valve has a “quick connect”coupling, attach the coupling. Open the drainvalve in order to drain the crankcase. Afterthe oil has drained, close the drain valve.Disconnect the coupling.

d. If the engine does not have a drain valve or apump, remove an oil drain plug. Allow the oil todrain. After the oil has drained, clean the drainplug and clean the fitting for the drain plug.Install the drain plug. Tighten the drain plug to145 ± 15 N·m (105 ± 10 lb ft).

Note: Ensure that the dirty oil is thoroughly drainedfrom the pan. Caterpillar recommends a thoroughcleaning of the oil pan with a vacuum and with ragsin order to completely remove all of the old oil. Thiswill help prevent inaccurate oil analysis results and/orshortened life of the oil.

3. Replace the engine oil filter elements before fillingthe crankcase with new oil.

a. For the procedure to change the engine oilfilters, refer to the Operation and MaintenanceManual, “Engine Oil Filter - Change” topic(Maintenance Section).

NOTICEEngine damage can occur if the crankcase is filledabove the “FULL” mark on the oil level gauge (dip-stick).

An overfull crankcase can cause the crankshaft to dipinto the oil. This will reduce the power that is devel-oped and also force air bubbles into the oil. Thesebubbles (foam) can cause the following problems: re-duction of the oil's ability to lubricate, reduction of oilpressure, inadequate cooling, oil blowing out of thecrankcase breathers, and excessive oil consumption.

Excessive oil consumption will cause deposits to formon the pistons and in the combustion chamber. De-posits in the combustion chamber lead to the followingproblems: guttering of the valves, packing of carbonunder the piston rings, and wear of the cylinder liner.

If the oil level is above the “FULL” mark on the oil levelgauge, drain some of the oil immediately.

Note: For the appropriate oil to use, and forthe amount of oil to use, refer to this Operationand Maintenance Manual, “Refill Capacities andRecommendations” article (Maintenance Section).

4. Remove the oil filler cap. Fill the crankcasethrough the oil filler tube only. Clean the oil fillercap. Install the oil filler cap.

NOTICETo prevent crankshaft damage and to prevent bearingdamage, manually operate the prelube pump or crankthe engine with the fuel supply line closed for 15 to 30seconds. This will ensure that all of the oil filters arefilled with oil before the engine is started.

5. Close the fuel supply line. Crank the engine untilthe oil pressure gauge indicates 70 kPa (10 psi).Open the fuel supply line. Allow the starting motorto cool for two minutes before cranking again.

6. Follow this Operation and Maintenance Manual,“Starting The Engine” procedure (OperationSection). Operate the engine at low idle for twominutes. This will ensure that the lubricationsystem and the oil filters are filled with oil. Inspectthe engine for oil leaks. Ensure that the oil level isbetween the “ADD” and the “FULL” marks on the“LOW IDLE” side of the oil level gauge.

7. Stop the engine and allow the oil to drain back intothe sump for a minimum of ten minutes.

8. Remove the oil level gauge and check the oil level.Maintain the oil level between the “ADD” and the“FULL” marks on the “ENGINE STOPPED” side ofthe oil level gauge.


Engine Oil Filter - Change

i02895793

Engine Oil Filter - ChangeSMCS Code: 1308-510; 1308

Replace the engine oil filters when any of thefollowing conditions are met:

• The engine oil is changed.

• The engine oil filter differential pressure reaches100 kPa (15 psi).

• The engine oil filters have been used for 1000operating hours.

Replace the Oil Filter Elements



NOTICEEnsure that the engine is stopped before performingthis procedure. Attach a DONOTOPERATE tag to thestarting controls.





1. Remove oil drain plug (1). Drain the oil into asuitable container.

2. Remove spin-on oil filters (2) with a 2P-8250Strap Wrench As.

3. Reinstall the oil drain plug.


Mounting base and gasket

4. Clean the sealing surface of the mounting base.Ensure that all of the old gasket is removed.

5. Apply clean engine oil to the gasket of the newoil filter.

NOTICECaterpillar oil filters are built to Caterpillar speci-fications. Use of an oil filter not recommended byCaterpillar could result in severe engine damage tothe engine bearings, crankshaft, etc., as a result ofthe larger waste particles from unfiltered oil enteringthe engine lubricating system. Only use oil filtersrecommended by Caterpillar.

6. Place the oil filter in position. Tighten the oilfilter by hand until the gasket contacts the base.Tighten the oil filter by hand for an additional 1 fullturn (360 degrees). Do not overtighten the oil filter.

96 SEBU7681-14Maintenance SectionEngine Oil Level - Check

7. Check the oil level according to the instructions inthis Operation and Maintenance Manual, “EngineOil Level - Check”.

Inspect the Used Oil Filter ElementsCut the used oil filter element open with a 4C-5084Oil Filter Cutter Gp.

Remove the metal wrap. Cut the filter elementfree from the end caps. Spread apart the pleatsand inspect the element for metal debris. Due tonormal wear and friction, it is not uncommon to findsmall amounts of debris in the oil filter element.An excessive amount of debris in the elementmay indicate early wear or a pending failure. If anexcessive amount of debris is found in the oil filterelement, consult your Caterpillar dealer in order toarrange for further oil analysis.

Use a magnet to differentiate between the ferrousmetals and the nonferrous metals that are foundin the element. Ferrous metals may indicate wearon the steel and the cast iron parts of the engine.Nonferrous metals may indicate wear on thealuminum parts, the brass parts, or the bronze partsof the engine. Parts that may be affected include thefollowing components: main bearings, rod bearings,turbocharger bearings, and cylinder heads.

i02225089

Engine Oil Level - CheckSMCS Code: 1348-535-FLV

The most accurate check of the engine oil level isobtained when the engine is stopped.

g01122349Illustration 58(1) Engine oil level gauge (dipstick)

1. Remove the filler cap (not shown) in order toensure that the crankcase pressure is equal to theatmospheric pressure.

Excess pressure or a slight vacuum will affectengine oil level that is measured.

2. Ensure that engine oil level gauge (1) is seated.

g00735162Illustration 59(3) “ENGINE STOPPED WITH OIL COLD” side(4) “ENGINE AT LOW IDLE WITH WARM OIL” side(5) “ADD” mark(6) “FULL” mark

a. If the engine is stopped, remove the engine oillevel gauge. Observe the engine oil level on“ENGINE STOPPED WITH OIL COLD” side(3).

b. If the engine is operating, reduce the enginespeed to low idle. Remove the engine oil levelgauge and observe the engine oil level on“ENGINE AT LOW IDLE WITH WARM OIL”side (4).

The engine oil level should be between “ADD”mark (5) and “FULL” mark (6).

NOTICEEngine damage can occur if the crankcase is filledabove the “FULL” mark on the oil level gauge (dip-stick).

An overfull crankcase can cause the crankshaft to dipinto the oil. This will reduce the power that is devel-oped and also force air bubbles into the oil. Thesebubbles (foam) can cause the following problems: re-duction of the oil's ability to lubricate, reduction of oilpressure, inadequate cooling, oil blowing out of thecrankcase breathers, and excessive oil consumption.

Excessive oil consumption will cause deposits to formon the pistons and in the combustion chamber. De-posits in the combustion chamber lead to the followingproblems: guttering of the valves, packing of carbonunder the piston rings, and wear of the cylinder liner.

If the oil level is above the “FULL” mark on the oil levelgauge, drain some of the oil immediately.


Engine Oil Sample - Obtain

3. If necessary, add engine oil. For the correct engineoil to use, refer to this Operation and MaintenanceManual, “Refill Capacities and Recommendations”topic (Maintenance Section). Do not fill thecrankcase above the “FULL” mark on the engineoil level gauge. Clean the filler cap (2). Install thefiller cap.

4. Record the amount of engine oil that is added. Forthe next engine oil sample and analysis, includethe total amount of engine oil that has been addedsince the previous oil change. This will help toprovide the most accurate analysis.

i03542996

Engine Oil Sample - ObtainSMCS Code: 1348-554-SM

In addition to a good preventive maintenanceprogram, Caterpillar recommends using S·O·S oilanalysis at regularly scheduled intervals in orderto monitor the condition of the engine and themaintenance requirements of the engine. S·O·S oilanalysis provides infrared analysis, which is requiredfor determining nitration and oxidation levels.

Obtain the Sample and the Analysis

Hot oil and hot components can cause personalinjury. Do not allow hot oil or hot components tocontact the skin.

Before you take the oil sample, complete the Label,PEEP5031 for identification of the sample. In orderto help obtain the most accurate analysis, providethe following information:

• Engine model

• Service hours on the engine

• The number of hours that have accumulated sincethe last oil change

• The amount of oil that has been added since thelast oil change

To ensure that the sample is representative of theoil in the crankcase, obtain a warm, well mixed oilsample.

To avoid contamination of the oil samples, the toolsand the supplies that are used for obtaining oilsamples must be clean.

Caterpillar recommends using the sampling valvein order to obtain oil samples. The quality and theconsistency of the samples are better when thesampling valve is used. The location of the samplingvalve allows oil that is flowing under pressure to beobtained during normal engine operation.

The 169-8373 Fluid Sampling Bottle isrecommended for use with the sampling valve. Thefluid sampling bottle includes the parts that areneeded for obtaining oil samples. Instructions arealso provided.


If the engine is not equipped with a sampling valve,use the 1U-5718 Vacuum Pump. The pump isdesigned to accept sampling bottles. Disposabletubing must be attached to the pump for insertioninto the sump.

For instructions, see Special Publication, PEgj0047,“How To Take A Good S·O·S Oil Sample”. Consultyour Caterpillar dealer for complete information andassistance in establishing an S·O·S program for yourengine.

i02861779

Engine Protective Devices -CheckSMCS Code: 7400-535

Visual InspectionVisually check the condition of all gauges, sensorsand wiring. Look for wiring and components thatare loose, broken, or damaged. Damaged wiringor components should be repaired or replacedimmediately.

Calibration Check

NOTICEDuring testing, abnormal operating conditionsmust besimulated.

The tests must be performed correctly in order to pre-vent possible damage to the engine.

98 SEBU7681-14Maintenance SectionEngine Speed/Timing Sensor - Clean/Inspect

Alarms and shutoffs must function properly. Alarmsprovide timely warning to the operator. Shutoffs helpto prevent damage to the engine. It is impossibleto determine if the engine protective devices arein good working order during normal operation.Malfunctions must be simulated in order to test theengine protective devices. To prevent damage to theengine, only authorized service personnel or yourCaterpillar dealer should perform the tests.

Consult your Caterpillar dealer or refer to the ServiceManual for more information.

i03479900

Engine Speed/Timing Sensor -Clean/InspectSMCS Code: 1905-040; 1905-070; 1907-040;1907-070

An engine speed/timing sensor is mounted in theflywheel housing. The speed/timing sensor providesinformation about engine speed and the position ofthe crankshaft to the ECM. There are two possibletypes of speed/timing sensors: fixed head and sliphead.


Fixed head sensors (if equipped)


The fixed head sensor has a threaded end, andscrews directly into the flywheel housing.

1. Remove the speed sensor (1) from the housing.Check the condition of the plastic end of the speedsensors for wear and/or contaminants.

2. Clean the metal shavings and other debris fromthe face of the speed sensors.

3. Install the engine speed/timing sensor.

Slip head sensors (if equipped)1. Remove engine speed/timing sensor (1). Inspectthe condition of the end of the magnet. Look forsigns of wear and contaminants.

2. Clean any debris from the face of the magnet.


3. Check the tension of the slip head. Gentlyextend the slip head (2) for a minimum of 4 mm(0.16 inch). Then push back the slip head.

When the slip head has the correct tension, atleast 22 N (5 lb) of force is required to push in theslip head from the extended position.


Engine Valve Lash and Bridge - Adjust

NOTICEThe sliphead must be fully extended when the speed/timing sensor is installed so that the sensor maintainsthe correct clearance with the speed-timing wheel.If the correct clearance is not maintained, the signalfrom the sensor will not be generated.

Do not install the sensor between the teeth of thespeed-timing wheel. Damage to the sensor would re-sult. Before installing the sensor, ensure that a toothof the wheel is visible in the mounting hole for the sen-sor.

4. Install the engine speed/timing sensor.

a. Ensure that a tooth on the speed-timing wheelis visible in the mounting hole for the sensor.

b. Extend the slip head (2) by a minimum of 4 mm(0.16 inch).

c. Coat the threads of the sensor with 4C-5597Anti-Seize Compound.

Note: The slip head is designed to contact a toothduring the first revolution of the speed-timing wheel.For the maximum allowable clearance betweenthe slip head and the tooth, refer to the engine'sSpecifications manual.

d. Install the sensor. Tighten the locknut to40 ± 5 N·m (30 ± 4 lb ft).

i02754665

Engine Valve Lash and Bridge- AdjustSMCS Code: 1102-025; 1102

Ignition systems can cause electrical shocks.Avoid contacting the ignition system componentsand wiring.

Do not attempt to remove the valve covers whenthe engine is operating. The transformers aregrounded to the valve covers. Personal injury ordeath may result and the ignition system will bedamaged if the valve covers are removed duringengine operation. The engine will not operatewithout the valve covers.

For procedures on adjusting the valve bridge and theengine valve lash, refer to the following publications:

• Special Instruction, REHS0128, “Using the147-5482 Indicator Gauge for Valve Lash andValve Bridge Adjustment”

• The Systems Operation/Testing and Adjustingmanual for the engine

• The Specifications manual for the engine

Consult your Caterpillar dealer for assistance.

Valve BridgeCheck the valve bridge and adjust the valve bridge,if necessary. Perform the procedure for both valvebridges for each cylinder.

After the valve bridge for each cylinder is satisfactory,measure the valve lash.

Engine Valve Lash

NOTICEOnly qualified service personnel should perform thismaintenance. Refer to the Service Manual or yourCaterpillar dealer for the complete valve lash adjust-ment procedure.

Operation of Caterpillar engines with improper valveadjustments can reduce engine efficiency. This re-duced efficiency could result in excessive fuel usageand/or shortened engine component life. Impropervalve lash may also lead to valve failure, and result incatastrophic failure.

If the valve lash is within the tolerance, an adjustmentof the valve lash is NOT necessary.

Perform valve lash adjustment if the dimension is notwithin the tolerance. The valve bridge adjustmentmust be performed before making a valve lashadjustment.

Perform the valve lash setting when the engine iscold. After the engine has been shut down and thevalve covers are removed, the engine is consideredcold.

Before performing maintenance, prevent the entry offoreign matter into the top of the cylinder head andthe valve mechanism. Thoroughly clean the areaaround the valve mechanism covers.

For further information, refer to Systems OperationTest and Adjust, “Valve Lash and Valve BridgeAdjustment”.

100 SEBU7681-14Maintenance SectionFlexible Coupling - Inspect

i03523641

Flexible Coupling - InspectSMCS Code: 3279-040

Coupling Boot Maintenance

g01232244Illustration 63(1) 5N-3272 Rubber Coupling Boot(2) Wear step

(A) Thickness of a new boot(B) Replacement thickness

Inspect boot (1) at a minimum of 1500 hour serviceintervals. Look for wear steps (2) in boot (1). Ameasurement of the wear step can also be taken atthe same time. Use the results of the inspection toadjust the service interval.

Do not measure the wear step directly due todisplaced rubber material. Measure the thickness atthe highest point of wear. Refer to Table 17. Replaceboot (1) when the boot is worn to thickness (B).

Table 17

Dimensions for Usage of Boot (1)

A B

22.1 mm (0.870 inch) 14.1 mm (0.555 inch)(1)

(1) The boot must be replaced.

i01724567

Fuel Metering Valve - Check(Raptor)SMCS Code: 1741-535

g00886284Illustration 64(1) Fuel metering valve

For information regarding the fuel meteringvalve, refer to Installation and Operation Manual,SEBU7630, “Raptor Gas Regulation and MeteringValve/Actuator System for Caterpillar”.

i01949940

Fuel System Fuel FilterDifferential Pressure - CheckSMCS Code: 1261-535

A fuel filter differential pressure gauge must beinstalled in order to determine when the fuel filterrequires service. This gauge and the fuel filter aresupplied by the customer.

A fuel filter differential pressure gauge indicates thedifference in fuel pressure between the inlet sideand the outlet side of the fuel filter. The differentialpressure increases as the fuel filter becomesplugged.

Operate the engine at the rated rpm and at therated load. Check the fuel filter differential pressure.Service the fuel filter when the fuel filter differentialpressure reaches 1.7 kPa (0.25 psi).

For instructions, refer to Special Instruction,SEHS9298, “Installation and Maintenance ofGaseous Fuel Filters”. Consult your Caterpillar dealerfor assistance.


Fumes Disposal Filter - Drain

i01857938

Fumes Disposal Filter - DrainSMCS Code: 1074



Note: Always disconnect power to the fumescollector prior to servicing. The motor is protected bya thermal protector. If the motor is shut down due toexcessive heat, the motor will automatically restartwhen the protector resets.

1. Shut down the engine and the fumes disposalfilter.

g00947065Illustration 65(1) Drip leg(2) Condensation trap drain valve

2. Open drip leg (1) and drain the fluid into a suitablecontainer.

If the filter is installed and maintained properly, nomore than 28 g (1 ounce) of fluid will be drained.

If more than one 28 g (1 ounce) is drained, makesure that the filter is installed according to theinstructions in Special Instruction, REHS0883.Ensure that the system is operating properly.

3. Close the drip leg.

4. Open condensation trap drain valve (2) and drainthe fluid into a suitable container.

5. Close the condensation trap drain valve.

Resume normal operation.

i01601766

Fumes Disposal FilterDifferential Pressure - CheckSMCS Code: 1074

g00829797Illustration 66Pressure gauge on top of the filter

Check the differential pressure across the filterelement. Observe the pressure that is indicated bythe pressure gauge on top of the filter. Record themeasurement.

The restriction of a new element is approximately1.7 kPa (7 inches of H2O).

The normal restriction of the element is approximately5.7 to 9.95 kPa (23 to 40 inches of H2O).

• Replace the filter element when the differentialpressure reaches 11.2 kPa (45 inches of H2O).

• Replace the element after every year regardless ofthe differential pressure.

i01749518

Fumes Disposal Filter Element- ReplaceSMCS Code: 1074



102 SEBU7681-14Maintenance SectionGas Pressure Regulator Condensation - Drain

Note: Always disconnect power to the fumescollector prior to servicing. The motor is protected bya thermal protector. If the motor is shut down due toexcessive heat, the motor will automatically restartwhen the protector resets.

g00763796Illustration 67(1) Nuts and washers(2) Cover(3) Body(4) Filter element

Note: The filter element is mounted above theengine. A ladder or a platform will be required forservicing the element.

1. Remove three nuts and washers (1) in order toremove cover (2) from body (3).

2. Remove element (4).

3. Clean the inside of cover (2) and body (3).

4. Install new element (4) into body (3).

5. Place cover (2) in position and install three nutsand washers (1).

i01950516

Gas Pressure RegulatorCondensation - DrainSMCS Code: 1270-543

To collect condensation, drip legs should be installedin the following locations:

• Supply line for the gas pressure regulator

• Balance line for the gas pressure regulator

• Supply line to the gas shutoff valve

g01014926Illustration 68Cap on the drip leg for the gas supply line to the gas pressureregulator

1. Close the main gas supply valve.

2. Remove the caps from the drip legs.

3. Allow the moisture to drain into a suitablecontainer. Inspect the drip legs for debris. Cleanthe drip legs, if necessary.

4. Clean the caps. Install the caps.

5. Open the main gas supply valve.

i03214248

Generator - DrySMCS Code: 4450-569

NOTICEDo not operate the generator if the windings are wet. Ifthe generator is operated when the windings are wet,damage can occur due to insulation breakdown.

Personal injury or death can result from impropertroubleshooting and repair procedures.

The following troubleshooting and repair proce-dures should only be performed by qualified per-sonnel familiar with this equipment.

Refer to Safety Section, “Generator Isolating forMaintenance” for information regarding the procedureto safely isolate the generator.

When moisture is present or when moisture issuspected in a generator, the generator must bedried before being energized.


Generator - Dry

If the drying procedure does not restore the insulationresistance to an acceptable value, the winding shouldbe reconditioned.

Drying MethodsThe following methods can be used for drying agenerator:

• Self-circulating air method

• Oven method

• Controlled current method

• Energize the optional space heaters.

NOTICEDo not allow the winding temperature to exceed 85 °C(185.0 °F). Temperatures that are greater than 85 °C(185.0 °F) will damage the winding insulation.

Self-Circulating Air Method

Run the engine and disconnect the generator load.This will help circulate air. Operate the generatorspace heaters.

Oven Method

Place the entire generator inside a forced air dryingoven for four hours at 65 °C (149 °F).

NOTICEUse a forced air type oven rather than a radiant typeoven.

Radiant type ovens can cause localized overheating.

Controlled Current Method


External Power Source Circuit(1) Battery (12 VDC)(2) Rheostat (15 ohm 25 watt)(3) Exciter Field (Stator “L1”)

Table 18

TOOLS NEEDED

Quantity Part Number Description

1 225-8266 Clamp-onammeter (1200amperes)

1 External powersource circuit

Heat can be used in order to dry the generatorwindings. This heat can be created by allowing acontrolled current to flow through the generator. Nohigh voltages are generated during the followingprocedure. Therefore, insulation breakdown will notoccur.

1. Make an external power source. Refer toIllustration 69.

2. Disconnect F1+ from the voltage regulator.Disconnect F2- from the voltage regulator.Disconnect the generator load. Connect thegenerator output leads T0, T1, T2, and T3together. Install the clamp-on ammeter togenerator output lead T1.

Note:When the line current is measured on multiplelead units, measure the current in each conductorper phase. The currents can then be added.

3. Refer to Illustration 69. Adjust the rheostat to themaximum resistance value. Connect the externalpower source to wires F1+ and F2-.

4. Start the generator set. Run the generator set atidle speed.

104 SEBU7681-14Maintenance SectionGenerator - Inspect

NOTICEDo not exceed the rated phase current that is listed onthe generator nameplate. Exceeding the rated phasecurrent will easily damage the generator windings.

5. Monitor the phase current. In order to maintainuse of the circuits for the protection of safety, usethe control panel for the “EMCP 3” to graduallyincrease the engine rpm. Increase the engine rpmuntil one of the following conditions are met:

• The rated phase current is obtained.

• The full generator set speed is obtained.

6. If more phase current is necessary, slowly turn therheostat. Turn the rheostat until the rated phasecurrent is reached.

7. On an hourly basis, stop the drying procedure.Check the insulation resistance. Repeat the abovesteps until the insulation resistance is acceptable.

Guidelines for Space Heaters

1. Energize the space heaters when the generator isnot operating.

2. Maintain the winding temperature at least 5 °C(9 °F) over the ambient temperature. In orderto maintain the desired temperature in someconditions, a supplemental heat source ortemporary covers may be required.

3. Check the insulation resistance until the resistanceis acceptable.

Note: For more information on drying methods, referto Special Instruction, SEHS9124, “Cleaning andDrying of Electric Set Generators”.

i01880220

Generator - InspectSMCS Code: 4450-040



The high voltage that is produced by an operatinggenerator set can cause severe injury or death.Before performing any maintenance or repairs,ensure that the generator will not start.

Place the engine control switch in the “OFF” posi-tion. Attach “DO NOT OPERATE” tags to all start-ing controls. Disconnect the batteries or disablethe starting system. Lock out all switchgear andautomatic transfer switches that are associatedwith the generator.

Refer to Safety Section, “Generator Isolating forMaintenance” for information regarding the procedureto safely isolate the generator.

Proper maintenance of electrical equipment requiresperiodic visual examination of the generator andperiodic visual examination of the windings. Propermaintenance of electrical equipment also requiresappropriate electrical checks and appropriate thermalchecks. Insulation material should be examined forcracks. The insulation material should be examinedfor accumulations of dirt and dust. If there is aninsulation resistance value that is below normal, aconductive path may be present. This conductivepath may be made of one of the following materials:

• Carbon

• Salt

• Metal dust

• Dirt that is saturated with moisture

These contaminants will develop a conductive pathwhich may produce shorts. Cleaning is advisable ifheavy accumulations of dirt can be seen or if heavyaccumulations of dust can be seen. If excess dirt isthe cause of a restriction in the ventilation, cleaningis also advisable. Restricted ventilation will causeexcessive heating.

NOTICETo avoid the possibility of deterioration to the genera-tor windings, do not clean the generator unless thereis visual, electrical, or thermal evidence that dirt ispresent.

If harmful dirt accumulations are present, a varietyof cleaning techniques are available. The cleaningprocedure that is used may be determined by one ofthe items on the following list:

• The extent of the cleaning procedure that is beingattempted


Generator Bearing - Lubricate

• The type of enclosure of the generator

• The voltage rating of the generator

• The type of dirt that is being removed

Cleaning (Assembled Generators)Cleaning may be required at the point of installation.At this point, complete disassembly of the generatormay not be necessary or feasible. In this case,a vacuum cleaner should be used to pick up thefollowing items: dry dirt, dust, and carbon. This willprevent the spreading of these contaminants.

A small nonconductive tube may need to beconnected to the vacuum cleaner. This will allow thevacuum cleaner to clean the surfaces that are notexposed. After most of the dust has been removed,a small brush may be attached to the vacuum hosein order to loosen dirt that is more firmly attached tothe surface.

After the initial cleaning with a vacuum, compressedair may be used to remove the remaining dust anddirt. Compressed air that is used for cleaning shouldbe free of moisture and free of oil. Air pressureshould be a maximum of 210 kPa (30 psi) in order toprevent mechanical damage to the insulation. If theabove cleaning procedures are not effective, consulta Caterpillar dealer.

Cleaning (DisassembledGenerators)An initial insulation resistance check should bemade on the generator in order to confirm electricalintegrity. A minimum reading of one megohm wouldbe expected with severely contaminated generators.A zero megohm reading may indicate an insulationbreakdown. An insulation breakdown requires morethan cleaning. An insulation breakdown requiresrepair.

A high pressure wash is normally an effective wayto clean windings. This includes windings that havebeen exposed to flooding or windings that have beencontaminated by salt. A solution of hot water anddetergent is used for this method of cleaning.

A high pressure wash sprays a high velocity fluidstream of this solution over the generator that isbeing cleaned. This detergent washing is followed bymultiple sprays of clean water. The clean water isused in order to remove the detergent or the cleanwater is used in order to dilute the detergent.

Allow the generator to dry at room temperature.Check the insulation resistance. The insulationresistance should now be normal. If the insulationresistance is not normal, repeat the procedure. Itmay be necessary to use solvents if the generatoris contaminated with oil or if the generator iscontaminated with grease.

Note: For more information on drying methods, referto Special Instructions, SEHS9124, “Cleaning andDrying of Electric Set Generators”.

i03547528

Generator Bearing - LubricateSMCS Code: 4471-086

Lubricating Process (If Applicable)Note: If the generator already has a visible greasepoint, go to Step 4.

1. Remove either the louver assembly or the rearplate from the rear of the generator housing.

2. Remove the top grease pipe plug and remove thelower grease pipe plug.

3. Install a grease fitting in the grease pipe.

4. Grease the bearings with the appropriate greasefrom Table 19. Do not mix greases.

106 SEBU7681-14Maintenance SectionGenerator Bearing - Lubricate

Table 19

BearingPartNumber

BearingType

FrameSize

TemperatureMin/Max(1)

GreasePartNumber

Interval Weight Volume ShaftDiameter

108-1760Ball Bearing

321 BC225.0 mm(8.9 inch)OD

105.0 mm(4.1 inch) ID

680 −29 °C(−20.2 °F)minimum/80 °C(176 °F)maximum

2S-3230BearingLubricant

Every 2000servicehours or 12months

51.2 g(1.8 oz)

59 mL (2 oz) 105.0 mm(4.1 inch)


322 BC240.0 mm(9.4 inch)OD

110.0 mm(4.3 inch) ID

690 /800

−29 °C(−20.2 °F)/80 °C(176 °F)



51.2 g(1.8 oz)

59 mL (2 oz) 110.0 mm(4.3 inch)

139-0349RollerBearing

Roller 2900 /2800

−40 °C(−40 °F)/80 °C(176 °F)

MobilithSHC220

Every 250servicehours

2.8 g(0.1 oz)

NA 127.0 mm(5.0 inch)

139-0350RollerBearing

Roller 2900 /2800

−40 °C(−40 °F)/80 °C(176 °F)

MobilithSHC220

Every 250servicehours

2.8 g(0.1 oz)

NA 127.0 mm(5.0 inch)


326 BC280.0 mm(11.0 inch)OD

130.0 mm(5.1 inch) ID

820 /2600 /2700

−29 °C(−20.2 °F)/80 °C(176 °F)



51.2 g(1.8 oz)

59 mL (2 oz) 130.0 mm(5.1 inch)

241-4644Bearing

320 BC215.0 mm(8.5 inch)OD

100.0 mm(3.9 inch) ID

LC7 −29 °C(−20.2 °F)/60 °C(140 °F)(2)

UNIREXN3


60 g (2.1 oz) NA 100.0 mm(3.9 inch)

243-5220Bearing

315 BB160.0 mm(6.3 inch)OD

75.0 mm(3.0 inch)ID

LC6100/LC5000

−29 °C(−20.2 °F)/60 °C(140 °F)(2)

UNIREXN3

Non-regreasablebearing(3)

Non-regreasablebearing


75.0 mm(3.0 inch)

261-3545Bearing

307 BB80.0 mm(3.1 inch)OD

35.0 mm(1.4 inch)ID

LC2000 −29 °C(−20.2 °F)/50 °C(122 °F)(2)

UNIREXN3




35.0 mm(1.4 inch)

(continued)


Generator Bearing - Lubricate

(Table 19, contd)

BearingPartNumber

BearingType

FrameSize


GreasePartNumber


262-5921Bearing

307 BC80.0 mm(3.1 inch)OD

35.0 mm(1.4 inch)ID

LC2000 −29 °C(−20.2 °F)/60 °C(140 °F)(2)

UNIREXN3




35.0 mm(1.4 inch)

263-0161Bearing

309 BC100.0 mm(3.9 inch)OD

45.0 mm(1.8 inch)

LC3000 −29 °C(−20.2 °F)/60 °C(140 °F)(2)

UNIREXN3




45.0 mm(1.8 inch)

5P-2448Ball Bearing

315 BC160.0 mm(6.3 inch)OD

75.0 mm(3.0 inch)ID

580 /590

−29 °C(−20.2 °F)/80 °C(176 °F)



51.2 g(1.8 oz)

59 mL (2 oz) 75.0 mm(3.0 inch)

6Y-3955Ball Bearing

220 BC180.0 mm(7.1 inch)OD

100.0 mm(3.9 inch) ID

450 −29 °C(−20.2 °F)/80 °C(176 °F)



51.2 g(1.8 oz)

59 mL (2 oz) 100.0 mm(3.9 inch)

6Y-6488Ball Bearing

318 BC190.0 mm(7.5 inch)OD

90.0 mm(3.5 inch)

597 −29 °C(−20.2 °F)/80 °C(176 °F)



51.2 g(1.8 oz)

59 mL (2 oz) 90.0 mm(3.5 inch)


326 BC280.0 mm(11.0 inch)OD

130.0 mm(5.1 inch) ID

1800FR

−40 °C(−40 °F)/80 °C(176 °F)

EA6 Non-regreasablebearing(1)



130.0 mm(5.1 inch)


322 BC240.0 mm(9.4 inch)OD

110.0 mm(4.3 inch) ID

1600FR

−40 °C(−40 °F)/80 °C(176 °F)

EA6 Non-regreasablebearing(1)



110.0 mm(4.3 inch)

(continued)

108 SEBU7681-14Maintenance SectionGenerator Load - Check

(Table 19, contd)

BearingPartNumber

BearingType

FrameSize


GreasePartNumber


253-9789Bearing

320 BC215.0 mm(8.5 inch)OD

100.0 mm(3.9 inch) ID

1400FR

−29 °C(−20.2 °F)/80 °C(176 °F)

UNIREXN3




100.0 mm(3.9 inch)


018 BC140.0 mm(5.5 inch)OD

90.0 mm(3.5 inch)ID

498/499 −29 °C(−20.2 °F)/80 °C(176 °F)



51.2 g(1.8 oz)

59 mL (2 oz) 90.0 mm(3.5 inch)

(1) This temperature is for a generator set that is equipped with a resistive temperature detector (RTD).(2) Do not exceed 60 °C (140 °F) above the ambient temperature.(3) This bearing can not be greased. Refer to this Operation and Maintenance Manual, “Generator Bearing - Replace” article for informationconcerning the replacement of these bearings.

(2) Do not exceed 50 °C (122 °F) above the ambient temperature.

5. Wipe off the excess grease. Remove the topgrease fitting. Install the plug.

6. Operate the generator for one hour. This will allowthe grease to expand. The expanding grease willforce the excess grease from the cavity. Whenthe excess grease is forced from the cavity, theinternal pressure will be reduced. The generatorshould continue to operate until the grease stopspurging.

7. Stop the engine. Install the plug in the bottomgrease pipe. Wipe off the excess grease.

8. Install the louver assembly or install the rear plate.

i03642825

Generator Load - CheckSMCS Code: 4450-535-LA

During normal operation, monitor the power factorand monitor generator loading.

When a generator is installed or when a generatoris reconnected, ensure that the total current in anyone phase does not exceed the nameplate rating.Each phase should carry the same load. This allowsthe generator to work at the rated capacity. If onephase current exceeds the nameplate amperage,an electrical imbalance will occur. An electricalimbalance can result in an electrical overload and anelectrical imbalance can result in overheating.

The power factor can be referred to as the efficiencyof the load. This can be expressed as the ratio of kVAto actual kW. The power factor can be calculated bydividing kW by kVA. Power factor is expressed as adecimal. Power factor is used to mean the portionof current that is supplied to a system that is doinguseful work. The portion of the current that is notdoing useful work is absorbed in maintaining themagnetic field in motors. This current (reactive load)can be maintained without engine power.

Generator sets normally have a low idle setting thatis higher than industrial engines. Low idle will beapproximately 66 percent of the full speed that isachieved by 60 Hz units. This would be equal to 80percent of the full speed that is achieved by 50 Hzunits.

Some generator sets are equipped with Woodwardgovernors and some generator sets are equippedwith Caterpillar electronic governors. Thesegenerator sets have no low idle stop. On generatorsets with mechanical governors and generators thatare natural gas, the low idle is set at the factory.Adjustment of the low idle on these machines shouldonly be done by a Caterpillar dealer.

Note: Operating the generator set at low idle speedfor an extended time will cause some voltageregulators to shut off. The generator set must becompletely shut down and the generator set mustbe restarted. This will allow the voltage regulator toagain produce an output.

SEBU7681-14 109Maintenance SectionGenerator Set - Test

i01754617

Generator Set - TestSMCS Code: 4450-081

Personal injury or death can result from high volt-age.

When power generation equipment must be in op-eration to make tests and/or adjustments, highvoltage and current are present.

Improper test equipment can fail and present ahigh voltage shock hazard to its user.

Make sure the testing equipment is designed forand correctly operated for high voltage and cur-rent tests being made.

When servicing or repairing electric power gener-ation equipment:

• Make sure the unit is off-line (disconnectedfrom utility and/or other generators powerservice), and either locked out or tagged DONOT OPERATE.

• Make sure the generator engine is stopped.

• Make sure all batteries are disconnected.

• Make sure all capacitors are discharged.

Table 20

Tools Needed(1)

Part Number Part Quantity

6V-7070 DigitalMultimeter 1

146-4080 DigitalMultimeter 1

9U7330 DigitalMultimeter 1

(1) Any one of these multimeters may be used.

The generator set functional test is a simplified testthat can be performed in order to determine if thegenerator is functional. The generator set functionaltest should be performed on a generator set that isnot under load. The generator set functional testdetermines if the generator is operating at expectedvoltage and frequency levels. Perform this test at theregulator and terminal strips. Do not perform this testat the output connections.

The generator set functional test consists of thefollowing steps:

1. Stop the generator. Remove the panels in order toallow access to the regulator and control terminalstrips. Determine the part number for the regulator.Record the sensing voltage of the regulator. Thesensing voltage is 120 V ± 3%, 240 V ± 3%, or480 V ± 3%. If the multimeter has the capability,also record the frequency.

2. Verify that the generator set is ready to start. Startthe generator set and bring the generator set torated speed. Measure the sensing voltage with themultimeter on terminals 20-22, 22-24, and 20-24.If these voltages match the sensing voltage of theregulator and if these voltages are nearly equal,then the output of the generator at the bus barshould be the correct value.

3. If the voltages do not match the sensing voltageof the regulator, see the service manual for theregulator for further troubleshooting instructions.

i03112463

Generator Set Vibration -InspectSMCS Code: 4450-040-VI

Check for vibration damage. Vibration may cause thefollowing problems:

• Loose fittings

• Loose belts

• Excessive noise

• Cracked insulation

The following areas are susceptible to vibrationdamage:

• Stator output leads

• Protective sleeving

• Insulation

• Exposed electrical connections

• Transformers

• Fuses

• Capacitors

• Lightning arresters

110 SEBU7681-14Maintenance SectionHoses and Clamps - Inspect/Replace

When a generator set is installed a vibration plotshould be recorded in order to assist in diagnosingpotential problems. This vibration plot should beupdated yearly. The vibration plot should also beupdated when the generator set is moved. Refer toData Sheet, LEKQ4023, “Linear Vibration” for theallowable limits of vibration.

Contact the Caterpillar Dealer Service Tools groupfor information on ordering a vibration analyzer thatwill meet your needs.

i02394981

Hoses and Clamps -Inspect/ReplaceSMCS Code: 7554-040; 7554-510

Inspect all hoses. Leaks can be caused by thefollowing conditions:

• Cracking

• Softness

• Loose clamps

Replace hoses that are cracked or soft. Tighten anyloose clamps.

NOTICEDo not bend or strike high pressure lines. Do not in-stall bent or damaged lines, tubes or hoses. Repairany loose or damaged fuel and oil lines, tubes andhoses. Leaks can cause fires. Inspect all lines, tubesand hoses carefully. Tighten all connections to the rec-ommended torque.

Check for the following conditions:

• Fittings that are damaged or leaking

• Outer covering that is chafed or cut

• Exposed wire that is used for reinforcement

• Outer covering that is ballooning locally

• Flexible part of the hose that is kinked or crushed

• Armoring that is embedded in the outer covering

Each installation application can be different. Thedifferences depend on the following factors:

• Type of hose

• Type of fitting material

• Anticipated expansion and contraction of the hose

• Anticipated expansion and contraction of thefittings

Replace the Hoses and the Clamps1. Service the hoses and clamps according to thesystem:




Pressurized System: Hot coolant can cause seri-ous burns. To open the cooling system filler cap,stop the engine and wait until the cooling systemcomponents are cool. Loosen the cooling systempressure cap slowly in order to relieve the pres-sure.

a. Before servicing a coolant hose, stop theengine. Allow the engine to cool. Loosen thecooling system filler cap slowly in order torelieve any pressure. Remove the coolingsystem filler cap. Drain the coolant from thecooling system to a level that is below the hosethat is being replaced.



b. Before servicing an oil hose, stop the engine.Allow the engine to cool. Drain the oil from thesystem to a level that is below the hose thatis being replaced.


Ignition System Spark Plugs - Inspect/Replace

Personal injury can result from removing hoses orfittings in a pressure system.

Failure to relieve pressure can cause personal in-jury.

Do not disconnect or remove hoses or fittings un-til all pressure in the system has been relieved.

c. Before servicing a pressurized air hose, stopthe engine. Ensure that the air supply to thehose is OFF. Slowly release pressure from thesystem.

2. Remove the hose clamps.

3. Disconnect the old hose. Discard the hose.

4. Install a new hose.

5. Install the hose clamps with a torque wrench.For torques on hose clamps, see Specifications,SENR3130, “Torque Specifications”, “HoseClamps”.

6. After servicing the hose, restore the system to anoperational state according to the requirementsof the system:

a. If a coolant hose was serviced, refill the coolingsystem. Install the cooling system filler cap.Start the engine. Inspect the cooling systemfor leaks.

b. If an oil hose was serviced, refill the system tothe proper level. Start the engine. Inspect thesystem for leaks.

Personal injury or death can result from improp-erly checking for a leak.

Always use a board or cardboard when checkingfor a leak. Escaping air or fluid under pressure,even a pin-hole size leak, can penetrate body tis-sue causing serious injury, and possible death.

If fluid is injected into your skin, it must be treatedimmediately by a doctor familiar with this type ofinjury.

c. If a pressurized air hose was serviced, restoreair pressure to the system. Check for air leaks.

i02896855

Ignition System Spark Plugs -Inspect/Replace(Spark Plugs with AdjustableElectrode Gaps)SMCS Code: 1555-535

S/N: MAD1-Up

S/N: GZJ1-Up

S/N: GZK1-Up

S/N: LGS1-Up

S/N: HAT1-Up

Maintenance of the spark plugs is required in orderto achieve the following benefits:

• Normal fuel consumption

• Normal level of emissions

• Maximum service life of the spark plugs

The service life of the spark plugs is affected byfouling due to deposits from the oil and by peakvoltage. Maintenance of the ignition system is alsoaffected by voltage. Higher voltage is required byhigher inlet manifold air pressure, operation withleaner lean air/fuel ratios, a higher compressionratio, and retarding of ignition timing. Higher voltagereduces the service life of components such as sparkplugs, wires, and transformers.

The service life of spark plugs in applications withlow BTU can be affected by the conditions that arelisted above and by fuel related impacts. The poorignitability of low BTU fuels causes high voltage tofire the plug. Silicon fuel contaminants that are foundin gas with low BTU can cause fouling of the sparkplug due to deposits.

112 SEBU7681-14Maintenance SectionIgnition System Spark Plugs - Inspect/Replace

Removing the Spark Plug




(1) Cover(2) Wiring harness(3) Transformer(4) Seal(5) Spark plug(6) Valve cover

1. Remove cover (1).

2. Remove wire harness (2) from transformer (3).

3. Remove the two remaining bolts that securetransformer (3). Remove the transformer fromvalve cover (6).

4. Inspect O-ring seal (4). If the seal is hard, cracked,or melted, install a new seal.

Pressurized air can cause personal injury. Whenpressurized air is used for cleaning, wear a pro-tective face shield, protective clothing, and pro-tective shoes.

Note: Excessive buildup of oil in the spark plugwell is an indication of a damaged lip seal on thetransformer.

5. Debris may have collected in the spark plug well.Thoroughly remove any debris. Use compressedair. The maximum air pressure for cleaningpurposes must be below 207 kPa (30 psi). Ensurethat the area around the spark plug is clean andfree of dirt and debris.

6. Use a 4C-4601 deep well socket, an extension,and a breaker bar to loosen spark plug (5). Afterthe spark plug has been loosened, use the socketand extension to remove the spark plug by handin order to detect problems with the threads. Afterthe spark plug has been removed, discard theused spark plug gasket.

If the spark plug resists removal by hand, applypenetrating oil to the threads. To help the oil penetratethe threads, turn the spark plug back and forth untilthe spark plug is loose.

If the spark plug cannot be removed by hand, cleanthe threads with 9U-7511 Spark Plug Seat Cleaner.This tool scrapes debris from the seat and from thethreads in the cylinder head. Be sure to clean anydebris from the cylinder.

NOTICEDo not use a thread tap. A thread tap will removemetalunnecessarily. The threads could be stripped and thecylinder head could be damaged.

Inspecting the Spark PlugInspect the spark plug closely for damage. Thecondition of the spark plug can indicate the operatingcondition of the engine.


Ignition System Spark Plugs - Inspect/Replace

g00838300Illustration 71(1) Terminal post(2) Insulator(3) Shell(4) Gasket(5) Electrode

Terminal post (1) must not move. If the terminal postcan be moved by hand, carefully tighten the post intothe threads of the insulator. If the post cannot betightened, discard the spark plug.

Inspect insulator (2) for cracks. If a crack is found,discard the spark plug.

Faint marks may extend from shell (3) onto theinsulator. The marks may be a result of corona thatforms at the top of the shell. The conductor willdevelop a corona when a very high voltage potentialionizes the air. This is a normal condition. This is notan indication of leakage between the shell and theinsulator.

Inspect shell (3) for damage. Cracks can be causedby overtightening the spark plug. Overtightening canalso yield the metal which loosens the shell. Discardany spark plug that has a shell that is cracked orloose.


(6) Precious metal tips on the electrode and the ground strap

Caterpillar spark plugs have precious metal tips (6)on the electrode and the ground strap. This materialwill gradually erode. Use extreme care when you setthe electrode gap. Maintain even spacing and properalignment between the two precious metal surfaces.

Replace the spark plug if the precious metal is wornoff.

A light brown deposit or a beige deposit around theelectrode is produced by normal operation.

Deposits that are gray or black may be caused bythe following substances:

• Excessive oil

• Use of the wrong oil

• A substance that is introduced through the fuelsystem or the air system

• Poor combustion because of a rich air/fuel mixture

A spark plug can operate despite a buildup of ash.However, a buildup of ash can cover the electrodegap. This will cause misfire. Large deposits mayretain heat which can cause premature fuel ignition.This can lead to uncontrollable detonation.

Cleaning the Spark PlugThoroughly clean the spark plug. Do not use a wirebrush. Glass beads are the preferred method forcleaning.

Follow these guidelines for using glass beads:

• Always use clean glass beads.

• Only use glass beads on the electrode and theinsulator near the electrode.

• Do not use glass beads on any other area of thespark plug.

• Clean the rest of the spark plug with nonflammablesolvent.

Installing the Spark PlugNote: Use the 9U-7516 Spark Plug Gauge tomeasure the electrode gap. Do not use a flat feelergauge for measuring the electrode gap of used sparkplugs. A feeler gauge will incorrectly measure theactual electrode gap because the used preciousmetal tips are curved.

1. Before installing the spark plug, set the electrodegap according to the engine's Specificationsmanual.

114 SEBU7681-14Maintenance SectionIgnition System Spark Plugs - Replace

Adjust the electrode gap, if necessary. Bend theground strap at the existing bend. Then bend thestrap near the weld in order to achieve properalignment and even spacing between the twoprecious metal surfaces. Measure the electrodegap after the alignment. Correct the electrodegap, if necessary.

Note: Do not use anti-seize compound on sparkplugs. Most of the heat is transferred through thethreads and the seat area of the spark plug. Contactof the metal surfaces must be maintained in order toprovide the heat transfer that is required.

2. Ensure that the spark plug is clean and free of dirtand oil.

3. Always use a new gasket when a spark plug isinstalled. If a used spark plug is installed, place anew 9Y-6792 Spark Plug Gasket on the sparkplug. Orient the tabs of the gasket toward thespark plug's electrode gap. Otherwise, the gasketmay not seat properly. If a gasket for a spark plugis installed incorrectly, do not increase the torqueon the spark plug in order to improve the seal. Donot reuse the gasket. Install a new gasket.

NOTICEDo not overtighten the spark plug. The shell can becracked and the gasket can be deformed. The met-al can deform and the gasket can be damaged. Theshell can be stretched. This will loosen the seal that isbetween the shell and the insulator, allowing combus-tion pressure to blow past the seal. Serious damageto the engine can occur.

Use the proper torque.

4. Install the spark plug by hand until the spark plugbottoms out. Tighten the spark plug according tothe engine's Specifications manual.

5. Ensure that the transformer and the extension areclean and free from dirt and oil. Lubricate O-ringseal (4) (Illustration 70) with one of the followinglubricants:

• 4C-9504 Dielectric Grease

• 5N-5561 Silicone Lubricant

• 8T-9020 Dielectric Grease

6. Install the transformer. Orient the transformertoward the wiring harness. Carefully align thesocket of the transformer with the wiring harnessconnector. Connect the wiring harness.

7. Install the valve cover.

i02896755

Ignition System Spark Plugs -ReplaceSMCS Code: 1555-510

S/N: GZA1-Up

S/N: GSB1-Up

S/N: GZB1-Up

S/N: TJB1-Up

S/N: GZC1-Up

S/N: TJC1-Up

S/N: GZG1-Up

S/N: GZH1-Up

S/N: GZL1-Up

S/N: HAL1-Up

S/N: GZM1-Up

S/N: GZN1-Up

S/N: B9P1-Up

S/N: RLP1-Up

S/N: SSR1-Up

S/N: GAS1-Up

S/N: NGS1-Up

S/N: CWW1-Up

S/N: GTX1-Up

S/N: CWY1-Up

S/N: SLY1-Up

S/N: SXY1-Up

S/N: GZZ1-Up

Note: Condensation can form in spark plugs thathave precombustion chambers. This can causedifficulty for cold start-ups. To avoid condensation,maintain the coolant in the cylinder block at aminimum temperature of 43 °C (110 °F) continuously.


Ignition System Spark Plugs - Replace

The service life of the spark plugs is affected byfouling due to deposits from the oil and by peakvoltage. Maintenance of the ignition system is alsoaffected by voltage. Higher voltage is required byhigher inlet manifold air pressure, leaner air tofuel operation, a higher compression ratio, andretardation of the timing. Higher voltage reducesthe service life of components such as spark plugs,wires, and transformers.

The service life of the spark plug is different fordifferent applications. The expected service life of thespark plug is approximately 3000 service hours foran engine that is running on pipeline natural gas atstandard performance sheet settings and conditions.To help predict the spark plug's service life, useCaterpillar Electronic Technician (ET) to monitor the“Cylinder #X Transformer Secondary Output VoltagePercentage” parameter. The value of this parameterwill increase as the spark plug gap wears over time.Experience at the particular site will help to determinethe proper interval for replacement of the spark plugs.

If a diagnostic code is generated for the ignitiontransformer's secondary circuit, the spark plug mayneed to be replaced. Misfire and a cold cylinder areother indications of a worn spark plug. Use Cat ETto monitor the exhaust port temperatures in order tolocate a cold cylinder.

Removing the Spark Plug




(1) Cover(2) Wiring harness(3) Transformer(4) Seal(5) Spark plug(6) Valve cover

1. Remove cover (1).

2. Remove wire harness (2) from transformer (3).

3. Remove the two remaining bolts that securetransformer (3). Remove transformer (3) fromvalve cover (6).

4. Inspect O-ring seal (4). If the seal is hard, cracked,or melted, install a new seal.

Pressurized air can cause personal injury. Whenpressurized air is used for cleaning, wear a pro-tective face shield, protective clothing, and pro-tective shoes.

116 SEBU7681-14Maintenance SectionIgnition System Spark Plugs - Replace

Note: Excessive buildup of oil in the spark plugwell is an indication of a damaged lip seal on thetransformer.

5. Debris may have collected in the spark plug well.Thoroughly remove any debris. Use compressedair. The maximum air pressure for cleaningpurposes must be below 207 kPa (30 psi). Ensurethat the area around the spark plug is clean andfree of dirt and debris.

6. Use a 216-1685 deep well socket, an extension,and a breaker bar to loosen spark plug (5). Afterthe spark plug has been loosened, use the socketand extension to remove the spark plug by handin order to detect problems with the threads. Afterthe spark plug has been removed, discard theused spark plug gasket.

If the spark plug resists removal by hand, applypenetrating oil to the threads. To help the oil penetratethe threads, turn the spark plug back and forth untilthe spark plug is loose.

If the spark plug could not be removed by hand,clean the threads with a Spark Plug Seat Cleaner.This tool scrapes debris from the seat and from thethreads in the cylinder head. Be sure to clean anydebris from the cylinder.

NOTICEDo not use a thread tap. A thread tap will removemetalunnecessarily. The threads could be stripped and thecylinder head could be damaged.

Inspecting the Spark Plug

g00935078Illustration 74(7) Terminal post(8) Insulator(9) Shell(10) Gasket(11) Hole in the spark plug's precombustion chamber

Inspect the spark plug closely for damage. Thecondition of the spark plug can indicate the operatingcondition of the engine.

Terminal post (7) must not move. If the terminal postcan be moved by hand, carefully tighten the post intothe threads of the insulator. If the post cannot betightened, discard the spark plug.

Insulator (8) is covered with Teflon. If the cover iscracked or loose, discard the spark plug.

Faint marks may extend from shell (9) onto theinsulator. The marks may be a result of a coronathat forms at the top of the shell. The conductor willdevelop a corona when a very high voltage potentialionizes the air. This is a normal condition. This is notan indication of leakage between the shell and theinsulator.

Inspect shell (9) for damage. Cracks can be causedby overtightening the spark plug. Overtightening canalso yield the metal which loosens the shell. Discardany spark plug that has a shell that is cracked orloose.

Inspect the spark plug's precombustion chamberfor deposits. Make sure that holes (11) in the sparkplug's precombustion chamber are not blocked.

A light brown deposit or a beige deposit is producedby normal operation.

Deposits that are gray or black may be caused bythe following substances:

• Excessive oil

• Use of the wrong oil

• A substance that is introduced through the fuelsystem or the air system

• Poor combustion because of a rich air/fuel mixture

A spark plug can operate despite a buildup ofash. Large deposits may retain heat which cancause premature fuel ignition. This can lead touncontrollable detonation.

Cleaning the Spark PlugDo not use glass beads to clean the spark plug.The beads could enter the precombustion chamberthrough the holes. The beads could clog the holes inthe spark plug's precombustion chamber.

Use a brass wire brush to clean the spark plug. Becareful not to damage the Teflon cover.

Installing the Spark PlugNote: Do not use anti-seize compound on sparkplugs. Most of the heat is transferred through thethreads and the seat area of the spark plug. Contactof the metal surfaces must be maintained in order toprovide the heat transfer that is required.

1. Ensure that the spark plug is clean and free of dirtand oil.


Ignition System Timing - Check/Adjust

2. Always use a new gasket when a spark plug isinstalled. If a used spark plug is installed, place anew gasket on the spark plug. Orient the tabs ofthe gasket toward the spark plug's precombustionchamber. Otherwise, the gasket may not seatproperly. If a gasket for a spark plug is installedincorrectly, do not increase the torque on the sparkplug in order to improve the seal. Do not reuse thegasket. Install a new gasket.

NOTICEDo not overtighten the spark plug. The shell can becracked and the gasket can be deformed. The met-al can deform and the gasket can be damaged. Theshell can be stretched. This will loosen the seal that isbetween the shell and the insulator, allowing combus-tion pressure to blow past the seal. Serious damageto the engine can occur.

Use the proper torque.

3. Install spark plug (5) by hand until the spark plugcontacts the gasket. Torque the spark plug tothe proper specification. Refer to Specifications,“Spark Plug” for the proper torque specification.

4. Ensure that the transformer and the extension areclean and free from dirt and oil. Lubricate O-ringseal (4) with one of the following lubricants:

• Dielectric Grease

• Silicone Lubricant

5. Install transformer (3). Orient the transformertoward wiring harness (2). Connect the wiringharness.

6. Install cover (1).

i03460071

Ignition System Timing -Check/AdjustSMCS Code: 1550-025; 1550-535

Ignition timing for gas engines varies with the gaschemistry. Obtain a fuel analysis in order to determineif the timing for the ignition system is correct. Enterthe data from the fuel analysis into the CaterpillarSoftware Program, LEKQ6378, “Methane NumberProgram”. Alternatively, you may provide the resultsof a gas analysis to your Caterpillar dealer forassistance in determining the correct timing for yourapplication.

Use the Caterpillar Electronic Technician (ET) toadjust the timing. Adjust the timing according tothe instructions in Special Instruction, REHS1438,“Installation and Initial Start-Up Procedures forG3500C and G3500E Engines”. Consult yourCaterpillar dealer for assistance.

i01935380

Inlet Air System - InspectSMCS Code: 1058-040; 1071-040; 1087-040

Use of a platform may be necessary to inspect thefollowing components of the air inlet system:

• Piping between the air cleaner and the turbocharger

• Rubber hoses in the air lines

• Turbocharger

• Piping between the turbocharger and theaftercooler

• Aftercooler

• Connection of the aftercooler to the air plenum

• Connection of the air plenum to the cylinder head

Inspect the components for the following conditions:

• Cracks

• Leaks

• Loose connections

• Debris

Ensure that all of the connections are secure. Ensurethat the components are in good condition and freeof debris.

Make repairs, if necessary. For information regardingremoval and installation of the components, referto Service Manual, “Disassembly and Assembly”.Consult your Caterpillar dealer for assistance.

118 SEBU7681-14Maintenance SectionInsulation - Test

i01689065

Insulation - TestSMCS Code: 4453-081; 4454-081; 4457-081;4470-081

Recommended Periodic InsulationTests



Note: The results from the insulation resistancechecks indicate when cleaning and/or repairing isbecoming critical. Generally, insulation resistancewill vary greatly with temperature. Therefore, alwaystest at the same temperature and humidity. Refer toIllustration 75.


Insulation - Test


120 SEBU7681-14Maintenance SectionInsulation - Test

Periodically, use an insulation tester to check theinsulation resistance of the generator's main statorwinding. Caterpillar recommends the 142-5055Insulation Testing Gp for testing the insulationresistance on Caterpillar generator sets. Thefrequency of this test is determined by the generator'senvironment. Previous insulation tester readings willalso determine the frequency of this test.

Test the main stator windings with an insulation testerin the following situations:

• The generator set is started for the first time.

• The generator set is removed from storage.

• The generator set is operating in a humidenvironment. Test every three months.

• The generator set is not protected from theelements in an enclosed area. Test every threemonths.

• The generator set is installed in an enclosed area.This area needs to be low in humidity and this areaneeds to have steady temperatures. Test everytwelve months (minimum).

• The generator set has not been run under load forthree months. Test the generator set weekly.

For additional information, refer to Special Instruction,SEHS9124, “Cleaning and Drying of Electric SetGenerators”.

Recommended Periodic InsulationTest Procedure

Personal injury or death can result from electro-cution.

The megohmmeter is applying a high voltage tothe circuit.

To avoid electrocution, do not touch the instru-ment leads without first discharging them. Whenfinished testing also discharge the generatorwindings.

1. Take the generator out of service.

2. Visually inspect the generator for moisture. Ifmoisture exists, do not perform this insulationtest. Dry the unit first. Refer to Special Instruction,SEHS9124, “Cleaning and Drying of Electric SetGenerators”.

3. Inspect the installation. Determine the equipmentthat will be tested by the insulation tester.

4. Discharge the capacitance of the windings.

5. Disconnect “T0” from ground.

6. Disconnect the regulator sensing lead wires: “20”,“22”, and “24”.

7. Connect the insulation tester's RED lead toground.

8. Connect the insulation tester's BLACK lead to“T0”.

9. For units that are 600 volts or less, set the voltageto 500 Volts. For units that are more than 600volts, set the voltage to 1000 Volts.

10.Use the 30/60 Time Resistance Method:

a. Apply voltage.

b. Observe the readings at 30 seconds. Observethe readings at 60 seconds.

c. Record the 60 second reading. This readingmust be corrected for temperature.

d. Record temperature.

e. Record humidity.

f. Remove voltage.

11.Evaluate the readings. The actual value of theresistance may vary greatly between generators.For this reason, the insulation's condition must beevaluated. Base this evaluation on the comparisonbetween the 60 second resistance readings andthe readings that were taken on previous dates.These two readings must be taken under similarconditions. If a 60 second resistance readinghas a 50 percent reduction from the previousreading, the insulation may have absorbed toomuch moisture.

Switch the insulation tester to the “OFF” position.This will discharge the insulation tester's leads.Disconnect the insulation tester's leads.

Engine Serial Number_____________________________________

Generator Serial Number_________________________________


Jacket Water Heater - Check

i03230758

Jacket Water Heater - CheckSMCS Code: 1383-535

Jacket water heaters help to improve startability inambient temperatures that are below 21 °C (70 °F).All installations that require automatic starting shouldhave jacket water heaters.

Check the operation of the jacket water heater. Checkthe operation of the circulation pump, if equipped. Foran ambient temperature of 0 °C (32 °F), the heatershould maintain the jacket water coolant temperatureat approximately 32 °C (90 °F).

i02902446

Oil Temperature Regulators -ReplaceSMCS Code: 1330

The oil temperature regulators divert the engineoil to the oil cooler in order to maintain engine oiltemperature.

For instructions on replacing the oil temperatureregulators, see the Service Manual, “Disassemblyand Assembly” module.

i03460083

Overhaul (In-Frame)SMCS Code: 1000-020

Scheduling an In-Frame OverhaulGenerally, an in-frame overhaul is performed forevery third top end overhaul. Scheduling an in-frameoverhaul normally depends on the following threeconditions:

• An increase of oil consumption

• An increase of crankcase blowby

• A decrease and a variation of cylinder compression

Each individual condition may not indicate a needfor an overhaul. However, evaluating the threeconditions together is the most accurate method ofdetermining when an overhaul is necessary.

The engine does not require an overhaul if theengine is operating within acceptable limits foroil consumption, crankcase blowby, and cylindercompression.

Periodically measure each of the three conditions.The first measurement should occur during theengine commissioning. This establishes a baselinefor future measurements. Additional measurementsare scheduled at regular intervals in order todetermine a schedule for the next in-frame overhaul.

The following changes in the three conditionsnormally require a scheduled overhaul:

• A 300 percent increase in oil consumption

• A 200 percent increase in crankcase blowby

• A 20 percent loss of cylinder compression

Note: These indications do not require an engineto be shut down for service. These indicationsonly mean that an engine should be scheduled forservice in the near future. If the engine operationis satisfactory, an immediate overhaul is not arequirement.

Monitor the engine as the engine accumulatesservice hours. Consult your Caterpillar dealer aboutscheduling a major overhaul.

Usually, an in-frame overhaul does not requireremoval of the engine. Instead, the service isperformed with the engine in place. If the customerrequires a minimum disruption in the production ofpower, the engine can be replaced with a rebuiltmodel of identical specifications.

Note: The generator or the driven equipment mayalso require service when the engine overhaul isperformed. Refer to the literature that is provided bythe OEM of the driven equipment.

In-Frame Overhaul InformationAn in-frame overhaul includes all of the work that isdone for a top end overhaul. Additionally, some othercomponents that wear are replaced. The conditionof components is inspected. Those components arereplaced, if necessary.

Your Caterpillar dealer can provide these servicesand components. Your Caterpillar dealer can ensurethat the components are operating within theappropriate specifications.

The following definitions explain the terminology forthe services that are performed during an overhaul:

122 SEBU7681-14Maintenance SectionOverhaul (Major)

Inspect – Inspect the components according tothe instructions that are in Caterpillar reusabilitypublications. Refer to Guidelines for ReusableParts and Salvage Operations, SEBF8029, “Indexof Publications on Reusability or Salvage of UsedParts”. The guidelines were developed in order tohelp Caterpillar dealers and customers to avoidunnecessary expenditures. New parts are notrequired if the existing parts can still be used,reconditioned, or repaired. If the components arenot in the reusability guidelines, refer to the ServiceManual, “Specifications” module.

Rebuild – The component can be reconditioned inorder to comply with reusability guidelines.

Replace – The service life of the part is exhausted.The part may fail before the next maintenanceinterval. The part must be replaced with a part thatmeets functional specifications. The replacementpart may be a new part, a CAT remanufactured part,a rebuilt part, or a used part. Some worn componentsmay be exchanged with your Caterpillar dealer.Consult your Caterpillar dealer about repair optionsfor your engine.

If you elect to perform an overhaul without theservices of a Caterpillar dealer, be aware of therecommendations in Table 21.

Table 21

In-Frame Overhaul

Clean Oil suction screen

CleanInspectTest

Aftercooler core

Compressor bypass valve

Exhaust system (landfill)

Fuel metering valve

Oil cooler

Oil pump

Pistons

Throttle

InspectRebuildReplace

Transformers and extenders

Prelube pump

Starting motor

Turbochargers

Rebuild

Water pumps

Connecting rod bearings

Cylinder head assemblies

Cylinder liners

Main bearings

Piston rings

Replace

Water temperature regulators

i03460103

Overhaul (Major)SMCS Code: 7595-020-MJ

Scheduling a Major OverhaulGenerally, a major overhaul is performed for everyfifth top end overhaul. The need for a major overhaulis determined by several factors. Some of thosefactors are the same factors that determine thein-frame overhaul:

• An increase of oil consumption

• An increase of crankcase blowby

• A decrease and variation of cylinder compression

Other factors must also be considered for determininga major overhaul:

• Power output


Overhaul (Major)

• The service hours of the engine

• Reduced oil pressure

• The wear metal analysis of the lube oil

• An increase in the levels of noise and vibration

An increase of wear metals in the lube oil indicatesthat the bearings and the surfaces that wear mayneed to be serviced. An increase in the levels ofnoise and vibration indicates that rotating partsrequire service.

Note: It is possible for oil analysis to indicate adecrease of wear metals in the lube oil. The cylinderliners may be worn so that polishing of the boreoccurs. Also, the increased use of lube oil will dilutethe wear metals.

Monitor the engine as the engine accumulatesservice hours. Consult your Caterpillar dealer aboutscheduling a major overhaul.

Note: The generator or driven equipment may alsorequire service when the engine is overhauled. Referto the literature that is provided by the OEM of thedriven equipment.

Major Overhaul InformationA major overhaul includes all of the work that isdone for top end overhauls and in-frame overhauls.Additional parts and labor are required in order tocompletely rebuild the engine. In some cases, theengine is relocated for disassembly.

For the major overhaul, all of the bearings,seals, gaskets, and components that wear aredisassembled. The parts are cleaned. The parts areinspected. If necessary, the parts are replaced. Thecrankshaft is measured for wear. The crankshaft mayrequire regrinding. Alternatively, the crankshaft maybe replaced with a Caterpillar replacement part.

Your Caterpillar dealer can provide these servicesand components. Your Caterpillar dealer can ensurethat the components are operating within theappropriate specifications.





If you elect to perform an overhaul without theservices of a Caterpillar dealer, be aware of therecommendations in Table 22. Your Caterpillar dealercan provide these services and components.

124 SEBU7681-14Maintenance SectionOverhaul (Top End)

Table 22

Major Overhaul


CleanInspectTest

Aftercooler core

Camshafts

Camshaft followers

Compressor bypass valve

Connecting rods

Crankshaft

Exhaust system (landfill)

Fuel metering valve

Gear train

Inlet air piping

Oil cooler

Oil pump

Pistons

Throttle valve

InspectRebuildReplace

Transformers and extenders

Prelube pump

Starting motor

Turbochargers

Water pumps

Rebuild

Vibration damper

Camshaft bearings

Connecting rod bearings

Coupling (tandem engines)

Cylinder liners

Gaskets and seals

Gear train bushings

Main bearings

Piston rings


Replace

Wiring harnesses

i03472462

Overhaul (Top End)SMCS Code: 7595-020-TE

Scheduling a Top End OverhaulTop end overhauls are scheduled according tothe recession of the exhaust valve stems. Thismeasurement provides an accurate indication of therate of valve wear. This measurement can be used topredict when a cylinder head requires replacement.

To determine a baseline, measure the projection ofthe exhaust valve stems after 100 to 250 servicehours. The baseline is a reference for subsequentmeasurements. Continue to periodically measurethe projection.

Plan for the top end overhaul as the valve stemprojection approaches the maximum limit. Performthe top end overhaul when the valve stem projectionhas increased by a total of 2.3 mm (.09 inch). Donot allow the projection of the exhaust valve stemsto exceed this limit.

Note: Generally, cylinder heads wear out at differentrates. In some cases, servicing the cylinder heads atdifferent times may be the most economic decision.This depends on the valve stem projection of theindividual cylinders. However, this decision mustinclude the costs of additional downtime that iscaused by this procedure. Perform an economicanalysis in order to determine if cylinder heads shouldbe serviced as a group or divided into smaller groups.

Note: The generator or the driven equipment mayalso require service when the engine overhaul isperformed. Refer to the literature that is provided bythe OEM of the driven equipment.

Top End Overhaul InformationA top end overhaul involves servicing the cylinderheads and turbochargers. Also, some other enginecomponents are inspected.

Top end overhauls require more tools than preventivemaintenance. The following tools are needed forrestoring the engine to factory specifications:

• Torque wrenches

• Dial indicators

• Accurate measurement tools

• Cleaning equipment

• Rebuilding equipment

SEBU7681-14 125Maintenance SectionOverhaul (Top End)

Caterpillar dealers are equipped with these tools.Caterpillar dealers can provide a flat rate price fora top end overhaul.

Unexpected problems may be found during a topend overhaul. Plan to correct these problems, ifnecessary.

• Buildup in the cylinders from excessive oilconsumption

• Buildup in the cylinders from contamination of thefuel

• Plugging of the aftercooler from coolant that ispoorly maintained

• Plugging of the aftercooler from contamination ofthe inlet air

• Degradation of the oil cooler from hydrogen sulfidein the fuel

• Deterioration of exhaust manifold components





If you elect to perform an overhaul without theservices of a Caterpillar dealer, be aware of therecommendations in Table 23. Your Caterpillar dealercan provide these services and components. YourCaterpillar dealer can ensure that the componentsare operating within the appropriate specifications.

Table 23

Top End Overhaul


CleanInspectTest

Aftercooler coreOil cooler coreExhaust manifolds

Inspect Transformers

Prelube pump

Starting motor

Turbochargers

Rebuild

Water pumps

Cylinder head assemblies

Spark plugs

Replace


Cleaning and Inspection of Components

Aftercooler and Oil Cooler

Clean the aftercooler core and the oil coolercore. Pressure test the components. Replace thecomponents, if necessary.

Note: If the cooling system is not properly maintained,cleaning of the aftercooler can be difficult. The tankthat is opposite of the inlet port and the outlet portcan not be removed for cleaning.

Note: This procedure may be used for cleaning boththe aftercooler core and the oil cooler core.

1. Remove the core.

2. Turn the core upside-down in order to removedebris.

NOTICEDo not use a high concentration of caustic cleaner toclean the core. A high concentration of caustic cleanercan attack the internal metals of the core and causeleakage. Only use the recommended concentration ofcleaner.

3. Back flush the core with cleaner.

Caterpillar recommends the use of Hydrosolvliquid cleaner. Consult your Caterpillar dealer forpart numbers and sizes of containers.

Use a two to five percent concentration of thecleaner at temperatures up to 93°C (200°F).

126 SEBU7681-14Maintenance SectionOverhaul (Top End)

4. Steam clean the core in order to remove anyresidue. Flush the fins of the core. Remove anyother trapped debris.

5. Wash the core with hot, soapy water. Rinse thecore thoroughly with clean water.

Personal injury can result from air pressure.

Personal injury can result without following prop-er procedure.When using pressure air, wear a pro-tective face shield and protective clothing.

Maximum air pressure at the nozzle must be lessthan 205 kPa (30 psi) for cleaning purposes.

6. Dry the core with compressed air. Direct the air inthe reverse direction of the normal flow.

Note: The test pressure for the oil cooler is 790 kPa(115 psi). The maximum differential pressure of waterfor the aftercooler is 44 kPa (6 psi). The maximumdifferential pressure of air for the aftercooler is5.1 kPa (0.74 psi).

7. Inspect the core in order to ensure cleanliness.Pressure test the core. Many shops that serviceradiators are equipped to perform pressure tests.If necessary, repair the core.

8. Install the core.

For more information on cleaning the cores, consultyour Caterpillar dealer.

Oil Suction Screen



Clean the oil suction screen after the engine oil panhas been drained.

Note: Approximately 1 L (1 qt) of engine oil willremain in the housing after the sump has beencompletely drained. This engine oil will pour out ofthe housing when cover (1) is removed. Prepare tocatch the engine oil in a pan. Clean up any spills withabsorbent towels or pillows. DO NOT use absorbentparticles.

g00760655Illustration 76(1) Cover(2) O-ring seal(3) Screen assembly

1. Loosen the bolts from cover (1). Remove cover(1) and O-ring seal (2). Discard the seal. Removescreen assembly (3).

2. Wash screen assembly (3) in clean nonflammablesolvent. Allow the screen assembly to dry beforeinstallation.

3. Clean the engine oil sump. Remove the sidecovers in order to gain access to the sump. Afterthe sump is clean, install the side covers.

4. Inspect screen assembly (3) for good condition.Obtain a new screen assembly, if necessary.Install the screen assembly. Install a new O-ringseal (2). Install cover (1).

Transformers

The transformers produce a voltage increase. Forgood operation, the connections must be clean andsecure. Inspect the transformers for the followingconditions:

• Damaged O-rings

• Dirty insulator


• Loose connector

• Moisture

Measure the voltage of the diode for the primarycircuit and measure the resistance of the secondarycircuit according to Troubleshooting, “G3500CEngines”. Consult your Caterpillar dealer forassistance.


Overhaul Considerations

i01950926

Overhaul ConsiderationsSMCS Code: 7595-043

Overhaul InformationAn overhaul is replacing the major worn componentsof the engine. An overhaul is a maintenance intervalthat is planned. The engine is rebuilt with certainrebuilt parts or new parts that replace the worn parts.

An overhaul also includes the following maintenance:

• Inspection of all the parts that are visible duringthe disassembly

• Replacement of the seals and gaskets that areremoved

• Cleaning of the internal passages of the engineand the engine block

Most owners will save money by overhauling theengine at the intervals that are recommended inthe Operation and Maintenance Manual. It is notpractical to wait until the engine exhibits symptomsof excessive wear or failure. It is not less costly towait. A planned overhaul before failure may be thebest value for the following reasons:

• Costly unplanned downtime can be avoided.

• Many original parts can be reused according to theguidelines for reusable parts.

• The service life of the engine can be extendedwithout the risk of a major catastrophe due toengine failure.

• Achieve the best cost/value relationship per hourof extended service life.

Overhaul Intervals

Top end overhauls are determined by the projectionof exhaust valve stems. In-frame overhauls aredetermined by cylinder compression, crankcaseblowby, and oil consumption. Major overhauls aredetermined by the in-frame tests, and by results ofS·O·S oil analysis.

Some other factors that are important for determiningthe overhaul intervals include the followingconsiderations:

• Performance of preventive maintenance

• Use of recommended lubricants

• Use of recommended coolants

• Use of recommended fuels

• Proper installation

• Operating conditions

• Operation within acceptable limits

• Engine load

• Engine speed

Note: To avoid oil problems, engines that areturbocharged and aftercooled must be operated at aminimum of 60 percent of rated load.

Generally, engines that are operated at a reducedload and/or speed achieve more service life beforean overhaul. However, this is for engines that areproperly operated and maintained.

Overhaul Inspection

Refer to the Service Manual for the disassembly andassembly procedures that are necessary in orderto perform the required maintenance on the itemsthat are listed. Consult your Caterpillar dealer forassistance.

To determine the reusability publications that areneeded to inspect the engine, refer to Guidelines forReusable Parts and Salvage Operations, SEBF8029,“Index of Publications on Reusability or Salvage ofUsed Parts”.

The Guidelines For Reusable Parts and SalvageOperations is part of an established Caterpillarparts reusability program. These guidelines weredeveloped in order to assist Caterpillar dealers andcustomers reduce costs by avoiding unnecessaryexpenditures for new parts. If the engine parts complywith the established inspection specifications, theparts can be reused. New parts are not necessary ifthe old parts can be reused, repaired, or salvaged.

If the parts are not within the inspection specifications,the parts should be salvaged, repaired, replaced,or exchanged. The use of out-of-spec parts couldresult in unscheduled downtime and/or costly repairs.The use of out-of-spec parts can also contribute toincreased fuel consumption and reduction of engineefficiency.

Your Caterpillar dealer can provide the parts that areneeded to rebuild the engine at the least possiblecost.

128 SEBU7681-14Maintenance SectionPower Factor - Check

Overhaul Programs

An economical way to obtain most of the partsthat are needed for overhauls is to use Caterpillarremanufactured parts. Caterpillar remanufacturedparts are available at a fraction of the cost of newparts. These parts have been rebuilt by Caterpillarand certified for use. The following components areexamples of the remanufactured parts:

• Alternators

• Connecting rods

• Crankshafts

• Cylinder heads

• Oil Pumps

• Starting motors

• Turbochargers

• Water pumps

Consult your Caterpillar dealer for details and for alist of the remanufactured parts that are available.

Your Caterpillar dealer may be offering a variety ofoverhaul options.

A Flat Rate Overhaul guarantees the maximum pricethat you will pay for an overhaul. Flat rate prices onpreventive maintenance programs or major repairoptions are available from many servicing dealersfor all Caterpillar Engines. Consult your Caterpillardealer in order to schedule a before failure overhaul.

Overhaul Recommendation

Caterpillar recommends a scheduled overhaul inorder to minimize downtime. A scheduled overhaulwill provide the lowest cost and the greatest value.Schedule an overhaul with your Caterpillar dealer.

Overhaul programs vary between dealers. To obtainspecific information about the types of overhaulprograms and services, consult your Caterpillardealer.

i01216962

Power Factor - CheckSMCS Code: 4450-535-PWR

The power factor of a system can be determined bya power factor meter or by calculations. The powerfactor can be calculated by dividing kW by kVA.Power factor is expressed as a decimal.

i02559063

Radiator - CleanSMCS Code: 1353-070

Note: Adjust the frequency of cleaning according tothe effects of the operating environment.

Inspect the radiator for these items: damaged fins,corrosion, dirt, grease, insects, leaves, oil, and otherdebris. Clean the radiator, if necessary.

Personal injury can result from air pressure.

Personal injury can result without following prop-er procedure.When using pressure air, wear a pro-tective face shield and protective clothing.

The maximum air pressure for cleaning purposesmust be reduced to 205 kPa (30 psi) when the airnozzle is deadheaded.

Pressurized air is the preferred method for removingloose debris. Direct the air in the opposite directionof the fan's air flow. Hold the nozzle approximately6 mm (0.25 inch) away from the fins. Slowly move theair nozzle in a direction that is parallel with the tubes.This will remove debris that is between the tubes.

Pressurized water may also be used for cleaning.The maximum water pressure for cleaning purposesmust be less than 275 kPa (40 psi). Use pressurizedwater in order to soften mud. Clean the core fromboth sides.

Use a degreaser and steam for removal of oil andgrease. Clean both sides of the core. Wash the corewith detergent and hot water. Thoroughly rinse thecore with clean water.

After cleaning, start the engine and accelerate theengine to high idle rpm. This will help in the removalof debris and drying of the core. Stop the engine.Use a light bulb behind the core in order to inspectthe core for cleanliness. Repeat the cleaning, ifnecessary.

Inspect the fins for damage. Bent fins may be openedwith a “comb”. Inspect these items for good condition:welds, mounting brackets, air lines, connections,clamps, and seals. Make repairs, if necessary.

For more detailed information on cleaning andinspection, refer to Special Publication, SEBD0518,“Know Your Cooling System”.


Rotating Rectifier - Check

i02246950

Rotating Rectifier - CheckSMCS Code: 4465-535

Check the exciter armature. Ensure that the rotatingrectifier is tight. If a failure of a rectifier is suspected,proceed to the “Testing a Three-Diode RectifierBlock” section.

Testing a Three-Diode RectifierBlock



Three-Diode Rectifier Block (two pieces)

The following procedure tests all three diodes withina block. Check the positive rectifier block and thenegative rectifier block. If any meter reading does notfall within the given ranges, replace the rectifier block.

1. Set the digital multimeter on the diode range.Remove all leads from the rectifier block.

2. To test the negative rectifier block, follow thesesteps:

a. Place the red test lead on the negative “-”terminal. Place the black test lead on thefollowing rectifier terminals: “AC1”(3), “AC2”(4),and “AC3”(5). All readings on the meter shouldbe between 0.4 and 1.0.

b. Place the black test lead on the negative“-” terminal. Place the red test lead on thefollowing rectifier terminals: “AC1”(3), “AC2”(4),and “AC3”(5). In all cases, the meter shouldread “OL” (overload).

3. To test the positive rectifier block, follow thesesteps:

a. Place the red test lead on the positive “+”rectifier terminal. Place the black test leadon the following rectifier terminals: “AC1”(3),“AC2”(4), and “AC3”(5). In all cases, the metershould read “OL” (overload).

b. Place the black test lead on the positive “+”rectifier terminal. Place the red test lead on thefollowing rectifier terminals: “AC1”(3), “AC2”(4),and “AC3”(5). All readings on the meter shouldbe between 0.4 and 1.0.

Note: A shorted diode can cause damage to theexciter rotor. If a diode is shorted, check the exciterrotor. Refer to the Testing and Adjusting, “Winding -Test” and Testing and Adjusting, “Insulation - Test”.Perform these tests.

Note: This rectifier block also contains varistor “CR7”.“CR7” can be checked by measuring the resistancebetween the positive “+” rectifier terminal and thenegative “-” rectifier terminal. The resistance shouldbe a minimum of 15000.

i02985289

Space Heater - CheckSMCS Code: 4450-535-HTR

The space heater is attached to the rear bearingbracket. The space heater is located in thegenerator's exciter end.

130 SEBU7681-14Maintenance SectionStarting Motor - Inspect

g00610396Illustration 79Space Heater Connection Diagram

An SR5 generator can operate in high humidityconditions without problems. The humidity can be ashigh as 100% non-condensing humidity. However,problems can occur when the generator is idle andthe surrounding air is warmer than the generator.Moisture can form on the windings. Moisture willresult in poor performance or even damage to thewindings. Whenever the generator is not active, theoptional space heaters should be operated.

An external source is required to operate the spaceheaters. Both of the sources must be a single phase.This source can be either 115 vac or 230 vac. Whenthe external source is 50 hertz, 200 vac must beused. Refer to Illustration 79.

See your Caterpillar dealer for information onchecking your Caterpillar generator.

i01113939

Starting Motor - InspectSMCS Code: 1451-040; 1453-040

If the starting motor fails, the engine may not start inan emergency situation. A scheduled inspection ofthe starting motor is recommended.

The starting motor pinion and the flywheel ring gearmust be in good condition in order for the engineto start properly. The engine will not start if thestarting motor pinion does not engage the flywheelring gear. The teeth of the starting motor pinion andthe flywheel ring gear can be damaged because ofirregular engagement.

Inspect the starting motor for proper operation. Listenfor grinding when the engine is started. Inspect theteeth of the starting motor pinion and the flywheelring gear. Look for patterns of wear on the teeth. Lookfor teeth that are broken or chipped. If damaged teethare found, the starting motor pinion and the flywheelring gear must be replaced.

Electric Starting MotorNote: Problems with the electric starting motor canbe caused by the following conditions: malfunction ofthe solenoid and malfunction of the electric startingsystem.

Inspect the electrical system for the followingconditions:


• Corrosion

• Wires that are worn or frayed

• Cleanliness

Make repairs, if necessary.

Air Starting Motor

Personal injury or death can result from improp-erly checking for a leak.

Always use a board or cardboard when checkingfor a leak. Escaping air or fluid under pressure,even a pin-hole size leak, can penetrate body tis-sue causing serious injury, and possible death.

If fluid is injected into your skin, it must be treatedimmediately by a doctor familiar with this type ofinjury.

Inspect all of the components in the air circuit forthe starting motor. Inspect all of the air lines andconnections for leaks.

If the teeth of the starting motor pinion and/or theflywheel ring gear are damaged, the air circuit forthe starting motor must be examined in order todetermine the cause of the problem.

SEBU7681-14 131Maintenance SectionStator Lead - Check

Removal and Installation of theStarting MotorRefer to the Service Manual, “Disassembly andAssembly” module for information on removing thestarting motor and installing the starting motor.

Consult your Caterpillar dealer for assistance.

i03230840

Stator Lead - CheckSMCS Code: 4459-535

Ensure that the stator output leads are routed out ofthe generator in a manner that prevents the leadsfrom rubbing against metal objects.

Visually inspect the following areas for cracking andphysical damage:

• stator output leads

• protective sleeving

• insulation

i02514961

Stator Winding Temperature -Measure/RecordSMCS Code: 4453-082-TA

Some generators are provided with optional 100 OhmResistance Temperature Detectors (RTD). When thetemperature of the stator winding is suspected to behigh, measure the temperature. If the generator isfurnished with Resistance Temperature Detectors,the detectors are installed in the slots of the mainarmature (stator). The detectors are used withequipment that is available from the factory. Thisequipment is used in order to measure the mainarmature's winding temperature.

i02293325

Throttle Control Valve - CheckSMCS Code: 1269-535

If a decrease in performance is observed or if theEngine Control Module signals that there is a problemwith the manifold pressure, check the throttle.


Check the throttle for leaks. If necessary, removethe throttle according to the instructions in theDisassembly and Assembly manual. Inspect thethroat of the throttle for wear marks. Check for freemovement of the butterfly valve.

Inspect the gaskets for wear or damage. If necessary,replace the gaskets. Reinstall the throttle accordingto the instructions in the Disassembly and Assemblymanual.

i03643569

Turbocharger - InspectSMCS Code: 1052-040

Periodic inspection and cleaning is recommended forthe turbocharger. Fouling of the turbine wheels cancontribute to loss of engine power and overall lossof engine efficiency.

If the turbocharger fails during engine operation,damage to the turbocharger compressor wheeland/or to the engine may occur. Damage to theturbocharger compressor wheel could allow partsfrom the compressor wheel to enter an enginecylinder. This can cause additional damage to thepistons, the valves, and the cylinder head.

132 SEBU7681-14Maintenance SectionTurbocharger - Inspect

NOTICETurbocharger bearing failures can cause large quan-tities of oil to enter the air inlet and exhaust systems.Loss of engine lubricant can result in serious enginedamage.

Minor leakage of a turbocharger housing under ex-tended low idle operation should not cause problemsas long as a turbocharger bearing failure has not oc-curred.

When a turbocharger bearing failure is accompaniedby a significant engine performance loss (exhaustsmoke or engine rpm up at no load), do not continueengine operation until the turbocharger is repaired orreplaced.

An inspection of the turbocharger can minimizeunscheduled downtime. Also, the chance for potentialdamage to other engine parts is reduced.

Note: Turbocharger components require clearancesthat are precise. The turbocharger cartridge must bebalanced due to high rpm.

The following conditions can cause the turbochargerto be out-of-balance:

• The buildup of deposits

• Chipping and/or flaking of deposits

If the turbocharger must be removed for inspection,use caution. Do not break deposits from the turbinewheel. Do not attempt to clean the turbine wheel. Forinformation regarding removal and installation, seethe Disassembly and Assembly manual or consultyour Caterpillar dealer. For information about repairof the turbocharger or about replacement of theturbocharger, consult your Caterpillar dealer.

1. Remove the exhaust outlet piping and removethe air inlet piping from the turbocharger. Visuallyinspect the piping for the presence of oil.

2. Turn the compressor wheel and the turbine wheelby hand. The assembly should turn freely. Inspectthe compressor wheel and the turbine wheel forcontact with the turbocharger housing. Thereshould not be any visible signs of contact betweenthe turbine wheel or compressor wheel and theturbocharger housing. If there is any indication ofcontact between the rotating turbine wheel or thecompressor wheel and the turbocharger housing,the turbocharger should be reconditioned.

3. Check the compressor wheel for cleanliness.If only the inlet side of the wheel is dirty, dirtand/or moisture is passing through the air filteringsystem. If oil is found only on the back side of thewheel, there is a possibility of a failed turbochargeroil seal.

The presence of oil may be the result of extendedengine operation at low idle. The presence of oilmay also result from restriction of the inlet air(plugged air filters). This causes oil to leak pastthe seal for the turbocharger compressor.

If oil is found on the compressor wheel and/orat the air inlet, the source of the oil is the fuelcompressor or the PCV system.

Note: Deposits of ash and silicone can accumulateon the turbine wheel. Turbine wheel will becomeunbalanced when the deposits flake off. Theturbocharger cartridge must be replaced when thisoccurs. However, remove deposits from the housing.This will prevent wear on the blades of the newturbine wheel.

4. Inspect the turbine wheel and the nozzle fordeposits of ash and silicone. If deposits of 1.6 mm(0.06 inch) thickness are found or if the turbineis in contact with the housing, the turbochargermust be disassembled and cleaned. Removal ofthe deposits can be difficult.

5. Inspect the bore of the turbine housing forcorrosion and deposits.


Axial clearance

Note: The axial clearance is the free axialdisplacement of the rotor. The rotor is moved backand forth with an approximate force between 150 N(34 lb) and 200 N (45 lb). Tolerances are shown inTable 24. The deflection of the measuring devicecorresponds to the axial clearance.


Valve Stem Projection - Measure/Record

g01955369Illustration 82Radial clearance

Note: Radial clearance is the maximum possibledeflection at the hub of the impeller at reciprocalneutralizing of the radial bearing clearance. Radialclearance is measured with the measuring deviceon the hub of the compressor wheel. Tolerancesare shown in Table 25. The rotor is tilted with anapproximate force between 150 N (34 lb) and 200 N(45 lb). The total deflection corresponds to the radialclearance.

Note: Axial clearance and radial clearance mustbe measured after the cartridge group has beenremoved, but prior to reinstallation.

6. Check the axial clearance and radial clearance.

7. Clean the turbocharger compressor housing withstandard shop solvents and a soft bristle brush.

8. Fasten the air inlet piping and the exhaust outletpiping to the turbocharger housing.

Table 24

Axial Clearance(1)

TPC47 0.12 ± 0.04 mm(0.0047 ± 0.0015 inch)

TPC49 0.12 ± 0.04 mm(0.0047 ± 0.0015 inch)

TPS52 −.14 ± 0.04 mm(0.0055 ± 0.0015 inch)

(1) The clearances apply to new parts and used parts. Oil filmsare not taken into account. The values in the table are validat an ambient temperature of 20° C (68° F). The clearancestake account of manufacturing tolerances of the applicablecomponents.

Table 25

Radial Clearance(1)

TPC47 −.635 ± 0.265 mm(0.025 ± 0.010 inch)

TPC49 −.69 ± 0.29 mm(0.027 ± 0.011 inch)

TPS52 −.88 ± 0.27 mm(0.034 ± 0.010 inch)

(1) The clearances apply to new parts and used parts. Oil filmsare not taken into account. The values in the table are validat an ambient temperature of 20° C (68° F). The clearancestake account of manufacturing tolerances of the applicablecomponents.

i03470080

Valve Stem Projection -Measure/RecordSMCS Code: 1105-082

Valve Recession – The valves and the valve seatsare worn over time. This causes the valves to recedeinto the cylinder head. This condition is called “valverecession”.

The top end overhaul is typically scheduled accordingto the amount of valve recession. The amount ofvalve recession should be monitored on both intakeand exhaust valves. However, it is difficult to measurethe actual valve recession in the cylinder head.A simpler method is used to determine the valverecession:

• Measure the projection of the valve rotator abovethe cylinder head.

Measure the projection of the exhaust valve rotatorswith a 155-1536 Valve Recession Tool Group.Follow the instructions that are provided with the toolgroup.

Record the measurements on the Operation andMaintenance Manual, “Valve Data Sheet” (ReferenceMaterials Section).

• Measure the projection of the exhaust valverotators after 250 service hours. This measurementis the baseline. The baseline is a reference forsubsequent measurements.

• Measure the projection of the exhaust valverotators at the first 1000 service hours.

134 SEBU7681-14Maintenance SectionVaristor - Test

• Plan for the top end overhaul as the projection ofthe valve rotator approaches the maximum limit.Perform the top end overhaul when the projectionof the valve rotator has increased by a total of2.3 mm (0.09 inch). Do not allow the recessionof the exhaust valves to exceed this limit. Thevalve head can break. This will cause severedamage in the combustion chamber.

• Check the measurement data for a difference inthe valve recession that is greater than 1 mm(0.039 inch) for the valves that share a valvebridge. If this measurement is exceeded for twosuccessive measurements, replacement of thecylinder head is necessary.

i01494879

Varistor - TestSMCS Code: 4466-081

g00677004Illustration 83PMPE Generator Wiring Diagram(CR1-CR6) Diodes(CR7) Varistor(L1) Exciter field (stator)(L2) Exciter armature (rotor)(L3) Main field (rotor)(L4) Main armature (stator)(L5) Pilot exciter armature(PM) Permanent magnet(RFA) Rotating field assembly(CST) Customer supplied transformer

OhmmeterAn ohmmeter can be used to check a varistor(CR7). Place an ohmmeter across the varistor. Theresistance should be a minimum of 15000 ohms. Ifthe resistance is less than 15000 ohms, the varistoris faulty.

Test Light

g00555113Illustration 84Test Light

Refer to the test light that is shown in Illustration 84.Follow these steps in order to test the varistor:

1. Disconnect either lead of the varistor (CR7).

2. Place the test light across the varistor.

3. Observe the results. The lamp should not light.

4. Reverse the test light.

5. Observe the results. The lamp should not light.

If the test light illuminates in either direction, there isa short in the varistor. Replace any faulty varistorswith varistors that have comparable operatingcharacteristics. Include the following informationwhen a varistor is being ordered for replacement:

• Part number of the varistor

• Serial number of the generator

After the varistor has been replaced, verify that thestrapping of the field winding lead is securely woundon the shaft. Also, verify that the strapping of the fieldwinding lead is securely tied.


Voltage and Frequency - Check

i01189996

Voltage and Frequency - CheckSMCS Code: 4450-535-EL

Check for proper voltage and frequency setting.Check for stability.

Refer to the generator set Serial Plate for correctvoltage and frequency.

i02591373

Walk-Around InspectionSMCS Code: 1000-040



Inspect the Engine for Leaks andfor Loose ConnectionsA walk-around inspection should only take a fewminutes. When the time is taken to perform thesechecks, costly repairs and accidents can be avoided.

For maximum engine service life, make a thoroughinspection of the engine compartment before startingthe engine. Look for items such as oil leaks or coolantleaks, loose bolts, worn belts, loose connections andtrash buildup. Make repairs, as needed:

• The guards must be in the proper place. Repairdamaged guards or replace missing guards.

• Wipe all caps and plugs before the engine isserviced in order to reduce the chance of systemcontamination.

NOTICEFor any type of leak (coolant, lube, or fuel) clean up thefluid. If leaking is observed, find the source and correctthe leak. If leaking is suspected, check the fluid levelsmore often than recommended until the leak is foundor fixed, or until the suspicion of a leak is proved to beunwarranted.

NOTICEAccumulated grease and/or oil on an engine or deck isa fire hazard. Remove this debris with steam cleaningor high pressure water.

• Ensure that cooling lines are properly clamped.Check for leaks. Check the condition of all pipes.

• Inspect the water pump for coolant leaks.

Note: The water pump seal is lubricated by coolantin the cooling system. It is normal for a small amountof leakage to occur as the engine cools down andthe parts contract.

Excessive coolant leakage may indicate the needto replace the water pump seal. For the removal ofwater pump and the installation of water pump and/orseals, refer to the Service Manual for the engine orconsult your Caterpillar dealer.

• Inspect the lubrication system for leaks at the frontcrankshaft seal, the rear crankshaft seal, the oilpan, the oil filters and the valve cover.

• Inspect the Closed Crankcase Ventilation (CCV)filter, if equipped. If the restriction indicator isvisible, service the CCV.

• Inspect the fuel system for leaks. Look for loosefuel line clamps.

• Inspect the piping for the air inlet system and theelbows for cracks and for loose clamps.

• Inspect the alternator belt and the accessory drivebelts for cracks, breaks or other damage.

Belts for multiple groove pulleys must be replaced asmatched sets. If only one belt is replaced, the belt willcarry more load than the belts that are not replaced.The older belts are stretched. The additional load onthe new belt could cause the belt to break.

• Drain the water and the sediment from fuel tankson a daily basis in order to ensure that only cleanfuel enters the fuel system.

• Inspect the wiring and the wiring harnesses forloose connections and for worn wires or frayedwires.

• Inspect the ground strap for a good connection andfor good condition.

• Inspect the engine-to-frame ground strap for agood connection and for good condition.

136 SEBU7681-14Maintenance SectionWater Pump - Inspect

• Disconnect any battery chargers that are notprotected against the current drain of the startingmotor. Check the condition and the electrolyte levelof the batteries, unless the engine is equipped witha maintenance free battery.

• Check the condition of the gauges. Replace anygauges that are cracked. Replace any gauges thatcan not be calibrated.

Inspect the GeneratorRefer to Safety Section, “Generator Isolating forMaintenance” for information regarding the procedureto safely isolate the generator.

A visual inspection should be initially directed atthe areas that are most prone to damage anddeterioration. The most prone areas to damage anddeterioration are listed below:

Ground insulation – Ground insulation is insulationthat is intended to isolate components that arecarrying current from components that are notcarrying current.

Support insulation – Support insulation is usuallymade from one of the following items: a compressedlamination of fibrous materials, polyester, or felt padsthat have been impregnated with various types ofbonding agents.

There are many different types of damage that canoccur in these areas. Several of the different types ofdamage are listed below:

Thermal aging – Thermal aging can cause thedegradation of insulation or the deterioration ofinsulation. An examination of the coils may revealthat the insulation has expanded into the ventilationducts. This is the result of a loss of bond whichwill cause the insulation material to separate. Theinsulation material could also separate from theconductors on the windings.

Abrasion – The surfaces of coils and the surfacesof connectors may be damaged by abrasion. Thesesurfaces may also be damaged by contaminationfrom other sources. An example of these sourceswould be chemicals or abrasive substances.

Cracking – Cracking of insulation may result frommechanical stress. The structure that is used to bracethe stator winding will become loose if the problemis not corrected. Further mechanical damage orelectrical damage may also result.

Erosion – Erosion can be caused when foreignsubstances rub against the insulation that is on thesurface of the coil .

i01985173

Water Pump - InspectSMCS Code: 1361-040

A failed water pump might cause severe engineoverheating problems that could result in cracks inthe cylinder head, a piston seizure or other potentialdamage to the engine.

Visually inspect the water pump for leaks. If leakingof the water pump seals is observed, replace all ofthe water pump seals. Refer to the Service Manualfor the disassembly and assembly procedure.

Inspect the water pump for wear, cracks, pin holesand proper operation. Refer to the Service Manual orconsult your Caterpillar dealer if repair is needed orreplacement is needed.


Some water pumps have a filter in the weephole(1). This filter helps prevent dirt from entering thewater pump. Inspect the filter with a flashlight in orderto ensure that the filter is clean. Replace the filterannually or replace the filter when the filter becomesplugged.


Water Temperature Regulator - Replace

i03518000

Water Temperature Regulator -ReplaceSMCS Code: 1355-510


Replace the water temperature regulators (1) beforethe water temperature regulators fail. This is arecommended preventive maintenance practice.Replacing the water temperature regulators reducesthe chances for unscheduled downtime.

A water temperature regulator that fails in apartially opened position can cause overheating orovercooling of the engine.

A water temperature regulator that fails in the closedposition can cause excessive overheating. Excessiveoverheating could result in cracking of the cylinderhead or a seizure of the pistons.

A water temperature regulator that fails in the openposition will cause the engine operating temperatureto be too low during partial load operation. Lowengine operating temperatures during partial loadscould cause an excessive carbon buildup inside thecylinders. This excessive carbon buildup could resultin an accelerated wear of the piston rings and wearof the cylinder liner. Also, a low temperature canallow moisture to condense in the oil. This can formdamaging acids.

NOTICEFailure to replace the water temperature regulator ona regularly scheduled basis could cause severe en-gine damage.

Never operate an engine without the water tempera-ture regulator installed.

If the water temperature regulator is installed incor-rectly, the enginemay overheat, causing cylinder headdamage. Ensure that the new water temperature reg-ulator is installed in the original position.

For the procedure to replace the water temperatureregulators, see the Service Manual, “Disassemblyand Assembly” module. Consult your Caterpillardealer for assistance.

Note: If only the water temperature regulators arereplaced, drain the coolant from the cooling system toa level that is below the water temperature regulatorhousing.

138 SEBU7681-14Maintenance SectionWinding - Test

i01787397

Winding - TestSMCS Code: 4453-081; 4454-081; 4457-081;4470-081


PMPE Generator Wiring Diagram

(CR1-CR6) Diodes(CR7) Varistor(L1) Exciter field (stator)(L2) Exciter armature (rotor)(L3) Main field (rotor)(L4) Main armature (stator)(L5) Pilot exciter armature(PM) Permanent magnet(RFA) Rotating field assembly(CST) Customer supplied transformer

Table 26

Tools Needed

Part Number Part(1) Quantity

6V-7070 DigitalMultimeter 1

146-4080Digital

Multimeter(RS232)

1

(1) Only one multimeter is necessary for this test. Either of themultimeters that are shown will work.



Measure the resistance of the following windings:(L1), (L2), (L3), (L4), and (L5). The winding thatis being tested must be disconnected from theother components before the resistance can bemeasured. The following resistance measurementsare approximations. If the measured value isnot near the listed approximation, the winding isprobably damaged. For a more precise resistancevalue, consult the Technical Marketing Information(TMI). Refer to the generator arrangement that is inquestion.

Note: The winding temperature affects theresistance. When the winding temperature increases,the winding resistance also increases. Whenthe winding temperature decreases, the windingresistance also decreases. Therefore, a correctmeasurement can be performed only when thewinding is at room temperature.

The following armature windings have very littleresistance: (L2), (L4), and (L5). The resistance ofthese windings will measure near 0 ohms. Use amilliohmmeter to measure the resistance of thearmature windings.

Exciter Armature (Rotor) (L2) – less than 0.1 ohm

Main armature (Stator) (L4) – less than 0.1 ohm

Pilot Exciter Armature (L5) – less than 0.1 ohm

Use a multimeter in order to measure the resistanceof field windings (L1) and (L3).

Exciter Field (Stator) (L1) – approximately 3.0ohms to 6.0 ohms

Main Field (Rotor) (L3) – approximately 0.75 ohmsto 2.0 ohms

Note: There should be no continuity between anywinding and ground. There should be no continuitybetween any winding and another winding.

Documents

G3500C and G3500E Generator Sets-Maintenance Intervals