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COOLING
TABLE OF CONTENTS
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COOLINGDESCRIPTION
DESCRIPTION - COOLING SYSTEM . . . . . . . . 1DESCRIPTION - HOSE CLAMPS . . . . . . . . . . . 1
OPERATION - COOLING SYSTEM . . . . . . . . . . . 1DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLINGSYSTEM LEAK TEST. . . . . . . . . . . . . . . . . . . . 2
DIAGNOSIS AND TESTING - COOLINGSYSTEM FLOW CHECK . . . . . . . . . . . . . . . . . 2
DIAGNOSIS AND TESTING - COOLINGSYSTEM AERATION . . . . . . . . . . . . . . . . . . . . 2
DIAGNOSIS AND TESTING - COOLINGSYSTEM DEAERATION . . . . . . . . . . . . . . . . . . 3
STANDARD PROCEDURESTANDARD PROCEDURE - COOLING
SYSTEM DRAINING . . . . . . . . . . . . . . . . . . . . 3
STANDARD PROCEDURE - COOLINGSYSTEM FILLING . . . . . . . . . . . . . . . . . . . . . . 3
STANDARD PROCEDURE - ADDINGADDITIONAL COOLANT . . . . . . . . . . . . . . . . . 3
STANDARD PROCEDURE - COOLANTLEVEL CHECK . . . . . . . . . . . . . . . . . . . . . . . . 3
SPECIFICATIONSTORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SPECIAL TOOLSCOOLING SYSTEM . . . . . . . . . . . . . . . . . . . . . 4
ACCESSORY DRIVE . . . . . . . . . . . . . . . . . . . . . . . 5ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . 27
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEMThe cooling system components consist of a radia-
tor, electric fan motors, shroud, pressure cap, thermo-stat, transmission oil cooler, water pump, hoses,clamps, coolant, and a coolant pressure container tocomplete the circuit.
DESCRIPTION - HOSE CLAMPSThe cooling system uses spring type hose clamps.
If a spring type clamp replacement is necessary,replace with the original Mopart equipment springtype clamp.
CAUTION: A number or letter is stamped into thetongue of constant tension clamps. If replacementis necessary, use only a original equipment clampwith matching number or letter (Fig. 1).
OPERATION - COOLING SYSTEMThe engine cooling systems primary purpose is to
maintain engine temperature in a range that willprovide satisfactory engine performance and emissionlevels under all expected driving conditions. It alsoprovides hot water (coolant) for heater performanceand cooling for automatic transmission oil. It does
this by transferring heat from engine metal to cool-ant, moving this heated coolant to the radiator, andthen transferring this heat to the ambient air.
• When engine is cold: thermostat is closed, cool-ing system has no flow through the radiator. Thecoolant bypass flows through the engine only.
• When engine is warm: thermostat is open, cool-ing system has bypass flow and coolant flow throughradiator.
Fig. 1 Spring Clamp Size Location1 - SPRING CLAMP SIZE LOCATION
CS COOLING 7 - 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEMLEAK TEST
WARNING: THE WARNING WORDS “DO NOT OPENHOT” ON THE RADIATOR PRESSURE CAP IS ASAFETY PRECAUTION. WHEN HOT, PRESSUREBUILDS UP IN COOLING SYSTEM. TO PREVENTSCALDING OR INJURY, THE RADIATOR CAPSHOULD NOT BE REMOVED WHILE THE SYSTEMIS HOT OR UNDER PRESSURE.
With engine not running, remove coolant pressurecontainer cap and wipe the filler neck sealing seatclean.
Attach the Cooling System Tester 7700 or equiva-lent to the radiator, as shown in (Fig. 2) and apply104 kPa (15 psi) pressure. If the pressure drops morethan 13.8 kPa (2 psi) in 2 minutes, inspect all pointsfor external leaks.
All radiator and heater hoses should be shakenwhile at 104 kPa (15 psi), since some leaks occur onlywhile driving due to engine movement.
If there are no external leaks, after the gauge dialshows a drop in pressure, detach the tester. Startengine and run until the thermostat opens, allowingthe coolant to expand. Reattach the cooling systemtester. If the needle on the dial fluctuates it indicatesa combustion leak, usually a head gasket leak.
WARNING: WITH TOOL IN PLACE, PRESSURE WILLBUILD UP FAST. EXCESSIVE PRESSURE BUILT UP,BY CONTINUOUS ENGINE OPERATION, MUST BERELEASED TO A SAFE PRESSURE POINT. NEVERPERMIT PRESSURE TO EXCEED 138 kPa (20 psi).
If the needle on the dial does not fluctuate, raisethe engine rpm a few times. If an abnormal amountof coolant or steam emits from the tailpipe, it mayindicate a coolant leak caused by a faulty head gas-ket, cracked engine block, or cracked cylinder head.
There may be internal leaks that can be deter-mined by removing the oil dipstick. If water globulesappear intermixed with the oil it will indicate aninternal leak in the engine. If there is an internalleak, the engine must be disassembled for repair.
DIAGNOSIS AND TESTING - COOLING SYSTEMFLOW CHECK
To determine whether coolant is flowing throughthe cooling system, use the following procedure:
WARNING: DO NOT REMOVE THE COOLING SYS-TEM PRESSURE CAP OR ANY HOSE WITH THESYSTEM HOT AND UNDER PRESSURE BECAUSESERIOUS BURNS FROM COOLANT CAN OCCUR.
• If engine is cold, idle engine until normal oper-ating temperature is reached. Feel the upper radiatorhose. If it is hot, coolant is circulating.
DIAGNOSIS AND TESTING - COOLING SYSTEMAERATION
Low coolant level in a cross flow radiator willequalize in both tanks with engine off. With engineat running and at operating temperature, the highpressure inlet tank runs full and the low pressureoutlet tank drops, resulting in cooling system aera-tion. Aeration will draw air into the water pumpresulting in the following:
• High reading shown on the temperature gauge.• Loss of coolant flow through the heater core.• Corrosion in the cooling system.• Water pump seal may run dry, increasing the
risk of premature seal failure.• Combustion gas leaks into the coolant can also
cause the above problems.Fig. 2 Pressure Testing - Typical
7 - 2 COOLING CS
COOLING (Continued)
DIAGNOSIS AND TESTING - COOLING SYSTEMDEAERATION
Air can only be removed from the system by gath-ering under the pressure cap. On the next heat up itwill be pushed past the pressure cap into the coolantrecovery bottle by thermal expansion of the coolant.It then escapes to the atmosphere in the coolantrecovery bottle and is replaced with coolant on cooldown.
To effectively deaerate the system, multiple ther-mal cycles of the system may be required.
NOTE: Deaeration does not occur at engine idle—higher engine speeds are required. Normal drivingwill deaerate cooling system.
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLING SYSTEMDRAINING
WARNING: DO NOT REMOVE OR LOOSEN THECOOLANT PRESSURE CAP, CYLINDER BLOCKDRAIN PLUGS, OR THE DRAINCOCK WHEN THESYSTEM IS HOT AND UNDER PRESSUREBECAUSE SERIOUS BURNS FROM THE COOLANTCAN OCCUR.
(1) Without removing pressure cap and withsystem not under pressure, open the draincock.The draincock is located on the lower left side ofradiator (Fig. 3).
(2) After the coolant pressure container is empty,then remove coolant pressure cap.
(3) Remove the cylinder block drain plug(s).
STANDARD PROCEDURE - COOLING SYSTEMFILLING
Remove pressure cap and fill system, using a 50/50mix of Mopart Antifreeze/Coolant, 5 Year/100,000Mile Formula and distilled water.
Continue filling system until full. Be careful notto spill coolant on drive belts or the generator.For cooling system capacity, (Refer to LUBRICATION& MAINTENANCE/FLUID TYPES - SPECIFICA-TIONS).
Fill coolant pressure container to at least the MAXmark with 50/50 solution. It may be necessary to addcoolant to the coolant pressure container after threeor four warm up/cool down cycles to maintain coolantlevel between the MAX and MIN mark. This willallow trapped air to be removed from the system.
STANDARD PROCEDURE - ADDINGADDITIONAL COOLANT
The radiator cap should not be removed.When additional coolant is needed to maintain thislevel, it should be added to the coolant recovery/re-serve container. Use only 50/50 mix of ethylene glycoltype antifreeze and distilled water. For the recom-meded antifreeze/coolant type (Refer to LUBRICA-TION & MAINTENANCE/FLUID TYPES -SPECIFICATIONS).
CAUTION: Do not use well water, or suspect watersupply in cooling system. A 50/50 ethylene glycoland distilled water mix is recommended. For therecommeded antifreeze/coolant type (Refer toLUBRICATION & MAINTENANCE/FLUID TYPES -DESCRIPTION).
STANDARD PROCEDURE - COOLANT LEVELCHECK
NOTE: Do not remove pressure cap for routinecoolant level inspections.
The coolant reserve system provides a quick visualmethod for determining the coolant level withoutremoving the radiator cap. With the engine coldand not running, simply observe the level of thecoolant in the coolant pressure container. The coolantlevel should be between the MIN and MAX marks.
Fig. 3 Adirondack Location1 - LEFT SIDE FRAME RAIL2 - DRAINCOCK
CS COOLING 7 - 3
COOLING (Continued)
SPECIFICATIONS
TORQUE
DESCRIPTION N·m Ft.Lbs.
In.Lbs.
Accessory Drive Belt TensionerAssembly —Bolt
28 — 250
Engine Coolant TemperatureSensor
7 — 60
Generator & A/C CompressorDrive Belt Tensioner Assembly—Bolt
54 40 —
Coolant Outlet Connector/Thermostat Housing—Bolts
28 — 250
Water Pump 12 — 105
Water Pump Inlet Tube —Bolts 12 — 105
Water Pump Inlet Tube —Bolts 28 — 250
Water Pump Pulley —Bolts 28 — 250
Radiator to A/C Condenser—Screws
5 — 45
Radiator Fan—Screws 5 — 45
Radiator Mounting (UpperBracket)—Nuts
12 — 105
SPECIAL TOOLS
COOLING SYSTEM
Pliers 6094
Hose Clamp Pliers 8495
Cooling System Tester 7700
Coolant Refractometer 8286
7 - 4 COOLING CS
COOLING (Continued)
ACCESSORY DRIVE
TABLE OF CONTENTS
page page
BELT TENSIONERSREMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DRIVE BELTSDIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT . . . . . . . . . . . . . . . . . . . . . . . . . . 6REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 7INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 7
IDLER PULLEYREMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 8
BELT TENSIONERS
REMOVAL(1) Raise vehicle on hoist.(2) Remove the drive belt shield.(3) Remove the drive belt(Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).(4) Remove the belt tensioner (Fig. 1).
INSTALLATION(1) Install the belt tensioner and bolt. Tighten bolt
to 28 N·m (250 in. lbs.).(2) Install the drive belt (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-TION).
(3) Install the drive belt shield.(4) Lower the vehicle.
Fig. 1 BELT TENSIONER1 - BELT TENSIONER2 - BOLT
CS ACCESSORY DRIVE 7 - 5
DRIVE BELTS
DIAGNOSIS AND TESTING - ACCESSORY DRIVE BELTCONDITION POSSIBLE CAUSES CORRECTIONS
INSUFFICIENT ACCESSORYOUTPUT DUE TO BELT SLIPPAGE
1. Belt too loose 1. Replace belt
2. Belt excessively glazed or worn 2. Replace and tighten as specified
BELT SQUEAL WHENACCELERATING ENGINE
1. Belts too loose 1. Replace tensioner
2. Belt glazed 2. Replace belts
BELT SQUEAK AT IDLE 1. Belts too loose 1. Replace tensioner
2. Dirt or paint imbedded in belt 2. Replace belt
3. Non-uniform belt 3. Replace belt
4. Misaligned pulleys 4. Align accessories
5. Non-uniform groove or eccentricpulley
5. Replace pulley
BELT ROLLED OVER IN GROOVEOR BELT JUMPS OFF
1. Broken cord in belt 1. Replace belt
2. Belt too loose, or too tight 2. Replace tensioner
3. Misaligned pulleys 3. Align accessories
4. Non-uniform groove or eccentricpulley
4. Replace pulley
REMOVAL(1) Raise vehicle on hoist.(2) Remove the drive belt shield (Fig. 2).
WARNING: DO NOT ALLOW DRIVE BELT TEN-SIONER TO SNAP BACK, AS DAMAGE TO TEN-SIONER AND/OR PERSONAL INJURY COULDRESULT.
(3) Position a wrench on the belt tensioner lug(Fig. 3).
(4) Release belt tension by rotating the tensionercounterclockwise (Fig. 3).
(5) Remove the drive belt.(6) Carefully return tensioner to its relaxed posi-
tion.
Fig. 2 Accessory Drive Belt Splash Shield1 - ATTACHING SCREW2 - ATTACHING SCREWS3 - SPLASH SHIELD
Fig. 3 DRIVE BELT TENSION RELEASE1 - BELT TENSIONER LUG2 - WRENCH
7 - 6 ACCESSORY DRIVE CS
CLEANINGClean all foreign debris from belt pulley grooves.
The belt pulleys must be free of oil, grease, and cool-ants before installing the drive belt.
INSPECTIONBelt replacement under any or all of the following
conditions is required:• Excessive wear• Frayed cords• Severe glazingPoly-V Belt system may develop minor cracks
across the ribbed side (due to reverse bending). Theseminor cracks are considered normal and acceptable.Parallel cracks are not (Fig. 4).
NOTE: Do not use any type of belt dressing orrestorer on Poly-V Belts.
INSTALLATION(1) Route and position the drive belt onto all pul-
leys, except for the crankshaft (Fig. 5).
(2) Rotate belt tensioner counterclockwise untilbelt can be installed onto the crankshaft pulley (Fig.3). Slowly release belt tensioner.
(3) Verify belt is properly routed and engaged onall pulleys.
(4) Install drive belt shield and lower vehicle.Fig. 4 Drive Belt Inspection
1 - NORMAL CRACKS - BELT OK2 - NOT NORMAL CRACKS - REPLACE BELT
Fig. 5 ACCESSORY DRIVE BELT1 - GENERATOR2 - IDLER PULLEY3 - AUTOMATIC BELT TENIONER4 - POWER STEERING PUMP PULLEY5 - AIR CONDITIONING COMPRESSOR PULLEY6 - CRANKSHAFT PULLEY7 - ACCESSORY DRIVE BELT8 - IDLER PULLEY
CS ACCESSORY DRIVE 7 - 7
DRIVE BELTS (Continued)
IDLER PULLEY
REMOVAL(1) Remove the accessory drive belt(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -REMOVAL).
(2) Remove the bolt and the upper idler pulley.(3) Remove the bolt and the lower idler pulley
(Fig. 6).
INSTALLATION(1) Install bolt and loweridler pulley.(2) Install bolt and upper idler pulley(3) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -INSTALLATION).
Fig. 6 Idler Pulleys1 - BOLT2 - IDLER PULLEY
7 - 8 ACCESSORY DRIVE CS
ENGINE
TABLE OF CONTENTS
page page
ENGINEDIAGNOSIS AND TESTING - ENGINE
COOLING SYSTEM . . . . . . . . . . . . . . . . . . . . . 9CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 13
COOLANTDESCRIPTION - ENGINE COOLANT . . . . . . . . . 15DIAGNOSIS AND TESTING - COOLANT
CONCENTRATION TESTING . . . . . . . . . . . . . 15STANDARD PROCEDURE - COOLANT
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15COOLANT RECOVERY PRESS CONTAINER
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 16OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 16REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 16
RADIATOR FANOPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 17DIAGNOSIS AND TESTING - RADIATOR FAN
MOTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 18
ENGINE BLOCK HEATERDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 18OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 18REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 19
ENGINE COOLANT TEMP SENSORDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 19REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 19
ENGINE COOLANT THERMOSTATREMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 19HEATER SUPPLY TUBE
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 20
HOSE CLAMPSDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 20OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
RADIATORREMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 22
RADIATOR DRAINCOCKREMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 23
PRESSURE CAPDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 23OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 23DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLINGSYSTEM PRESSURE CAP TESTING . . . . . . . 23
DIAGNOSIS AND TESTING - PRESSURECAP TO FILLER NECK SEAL . . . . . . . . . . . . . 24
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 24
RADIATOR FAN RELAYDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 24OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 25REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 25
WATER PUMPDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 25REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 26INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 26
ENGINE
DIAGNOSIS AND TESTING - ENGINE COOLINGSYSTEM
Establish what driving condition caused the coolingsystem complaint. The problem may be caused by anabnormal load on the system such as the following:prolonged idle, very high ambient temperature, slighttail wind at idle, slow traffic speed, traffic jam, highspeed, steep grade.
DRIVING TECHNIQUESTo avoid overheating the cooling system:
(1) Idle with A/C off when temperature gauge is atend of normal range.
(2) Do not increase engine speed for more air flowand coolant flow because the electric motor fan sys-tems are not responsive to engine RPM. The addedcooling from higher coolant flow rate is more thanoffset by increased heat rejection (engine heat addedto coolant).
TRAILER TOWINGConsult the owner’s manual under Trailer Towing
and do not exceed specified limits.
CS ENGINE 7 - 9
VISUAL INSPECTIONIf the cooling system problem is not caused by a
driving condition, perform a visual inspection todetermine if there was a recent service or accidentrepair, including the following:
• Loose/damaged water pump drive belt• Incorrect cooling system refilling (trapped air or
low level)• Brakes possibly dragging• Damaged hoses• Loose/damaged hose clamps• Damaged/incorrect engine thermostat
• Damaged cooling fan motor, fan blade and fanshroud
• Damaged head gasket• Damaged water pump• Damaged radiator• Damaged coolant recovery system• Damaged heater core• Open/shorted electrical circuitsIf the visual inspection reveals none of the above
as cause for a cooling system complaint, refer to thefollowing diagnostic charts.
COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
PRESSURE CAP IS BLOWINGOFF STEAM AND/OR COOLANT.TEMPERATURE GAUGE READINGMAY BE ABOVE NORMAL BUTNOT HIGH. COOLANT LEVEL MAYBE HIGH IN COOLANT RESERVE/OVERFLOW TANK.
1. Pressure relief valve in pressurecap is defective, or was notproperly seated.
1. Check condition of pressure capand cap seal. (Refer to 7 -COOLING/ENGINE/RADIATORPRESSURE CAP - DIAGNOSISAND TESTING) Replace cap asnecessary.
2. Incorrect cap was installed. 2. Replace cap as necessary.
3. Incorrect coolant mixture. 3. Check concentration level of thecoolant. (Refer to 7 - COOLING/ENGINE/COOLANT - DIAGNOSISAND TESTING) Adjust the ethyleneglycol-to-water ratio as required.
COOLANT LOSS TO THEGROUND WITHOUT PRESSURECAP BLOWOFF. GAUGE ISREADING HIGH OR HOT.
1. Coolant leaks in radiator, coolingsystem hoses, water pump orengine.
1. Pressure test and repair asnecessary. (Refer to 7 - COOLING -DIAGNOSIS AND TESTING)
DETONATION OR PRE-IGNITION(NOT CAUSED BY IGNITIONSYSTEM). GAUGE MAY NOT BEREADING HIGH.
1. Engine overheating. 1. Check reason for overheatingand repair as necessary.
2. Freeze point of coolant notcorrect. Mixture too concentrated ortoo diluted.
2. Check concentration level of thecoolant. (Refer to 7 - COOLING/ENGINE/COOLANT - DIAGNOSISAND TESTING) Adjust the ethyleneglycol-to-water ratio as required.
3. Incorrect cooling systempressure cap.
3. Install correct pressure cap.
HOSE(S) COLLAPSE AS ENGINECOOLS DOWN.
1. Vacuum created in coolingsystem on engine cool-down is notbeing relieved through coolantrecovery system.
1. (a) Pressure cap relief valvestuck. (Refer to 7 - COOLING/ENGINE/RADIATOR PRESSURECAP - DIAGNOSIS AND TESTING)Replace as necessary.
(b) Hose between the radiator andoverflow container is plugged orpinched. Clean and repair asnecessary.
7 - 10 ENGINE CS
ENGINE (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
(c) Vent at coolant pressurecontainer is plugged. Clean ventand repair as necessary.
(d) Pressure container is internallyblocked. Clean and repair asnecessary.
INADEQUATE AIR CONDITIONERPERFORMANCE (COOLINGSYSTEM SUSPECTED).
1. Radiator and/or A/C condenser isrestricted, obstructed, or dirty(insects, leaves, etc.).
1. Remove restriction and/or cleanas necessary.
2. Electrical radiator fan notoperating when A/C is operated.
2. For test procedure (Refer toappropriate Diagnostic Information).Repair as necessary.
3. Engine is overheating (heat maybe transferred from radiator to A/Ccondenser). High underhoodtemperatures due to engineoverheating may also transfer heatto A/C components.
3. Correct overheating condition.
4. All models are equipped with airseals at the radiator and/or A/Ccondenser. If these seals aremissing or damaged, not enoughair flow will be pulled through theradiator and A/C condenser.
4. Check for missing or damaged airseals and repair as necessary.
INADEQUATE HEATERPERFORMANCE.
1. Check for a Diagnostic troublecode (DTC).
1. For procedures, (Refer toappropriate Diagnostic Information).Repair as necessary.
2. Coolant level low. 2. (Refer to 7 - COOLING -STANDARD PROCEDURE) Repairas necessary.
3. Obstructions in heater hosefitting at engine or at heater core.
3. Remove heater hoses at bothends and check for obstructions.Repair as necessary.
4. Heater hose kinked. 4. Locate kinked area and repair asnecessary.
5. Water pump is not pumpingcoolant to heater core.
5. When the engine is fully warmedup, both heater hoses should be hotto the touch. If only one of thehoses is hot, the water pump maynot be operating correctly. Replacecomponents as necessary.
6. Air trapped in heater core. 6. (Refer to 7 - COOLING -DIAGNOSIS AND TESTING)
CS ENGINE 7 - 11
ENGINE (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
HEAT ODOR 1. Various heat shields are used atcertain driveline components. Oneor more of these shields may bemissing.
1. Locate missing shields andreplace or repair as necessary.
2. Temperature gauge readingabove the normal range.
2. Refer to Gauge Is Reading Highin Temperature Gauge IndicaticationDiagnosis Chart.
3. Radiator fan operatingincorrectly.
3. (Refer to 7 - COOLING/ENGINE/RADIATOR FAN - OPERATION)Repair as necessary.
4. Undercoating been applied to anunnecessary component.
4. Clean undercoating as necessary.
5. Engine may be running rich,causing the catalytic converter tooverheat
5. (Refer to Appropriate DiagnosticInformation) Repair as necessary.
POOR DRIVEABILITY(THERMOSTAT POSSIBLY STUCKOPEN). GAUGE MAY BE READINGLOW.
1. The engine thermostat must beoperating correctly for properdriveability, clean vehicle emissions,and the prevention of sludgebuildup in the engine oil. Check fora diagnostic trouble code.
1. (Refer to Appropriate DiagnosticInformation) Replace thermostat, ifnecessary.
STEAM IS COMING FROM FRONTOF VEHICLE NEAR GRILL AREAWHEN WEATHER IS WET,ENGINE WARMED UP ANDRUNNING WITH VEHICLESTATIONARY, OR JUST SHUTOFF. TEMPERATURE GAUGE ISNORMAL.
1. During wet weather, moisture(snow, ice, rain, or condensation)on the radiator will evaporate whenthe thermostat opens. Thethermostat opening allows heatedcoolant into the radiator. When themoisture contacts the hot radiator,steam may be emitted. This usuallyoccurs in cold weather with no fanor air flow to blow it away.
1. Occasional steam emitting fromthis area is normal. No repair isnecessary.
COOLANT COLOR 1. Coolant color is not necessarilyan indication of adequate corrosionor temperature protection. Do notrely on coolant color for determiningcondition of coolant.
1. Check the freeze point of thecoolant. (Refer to 7 - COOLING/ENGINE/COOLANT - DIAGNOSISAND TESTING) Adjust the ethyleneglycol-to-water ratio as necessary.
COOLANT LEVEL CHANGES INCOOLANT BOTTLE.TEMPERATURE GAUGE IS INNORMAL RANGE.
1. Level changes are to beexpected as coolant volumefluctuates with engine temperature.The coolant level will also drop asthe system removes air from arecent filling.
1. A normal condition. No repair isnecessary.
Refer to (Fig. 1) when using the TEMPERATUREGAUGE INDICATION DIAGNOSIS CHART.
7 - 12 ENGINE CS
ENGINE (Continued)
TEMPERATURE GAUGE INDICATION DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READINGIS INCONSISTENT (FLUCTUATES,CYCLES OR IS ERRATIC).
1. Normal reaction to fan and/orthermostat cycle (Fig. 1 ),Examples B and C. During coldweather operation with the heaterblower in the high position, thegauge reading may drop slightly(Fig. 1 ), Example D. Fluctuation isalso influenced by outsidetemperature and heavy loads (Fig.1 ), Example E.
1. A normal condition. No correctionis necessary.
2. Gauge reading rises whenvehicle is brought to a stop afterheavy use (engine still running)(Fig. 1 ), Example F.
2. A normal condition. No correctionis necessary. Gauge reading shouldreturn to normal range (Fig. 1 ),Example A, after vehicle is driven.
3. Gauge reading high afterrestarting a warmed-up (hot)engine.
3. A normal condition. No correctionis necessary. The gauge shouldreturn to normal range (Fig. 1 ),Example A, after a few minutes ofengine operation.
4. Temperature gauge or enginecoolant temperature sensordefective or shorted. Also, corrodedor loose wiring in the electricalcircuit.
4. Check operation of gauge orengine coolant temperature sensorand repair, if necessary.
CLEANINGDrain cooling system and refill with clean water.
Refer to drain and fill procedures in this section. Runengine with radiator cap installed until upper radia-tor hose is hot. Stop engine and drain water fromsystem. If water is dirty; fill, run, and drain systemagain, until water runs clear. Refill cooling systemwith a 50/50 mixture of the recommended ethyleneglycol and distilled water (Refer to LUBRICATION &MAINTENANCE/FLUID TYPES - DESCRIPTION).
INSPECTIONAfter performing a cleaning/flush procedure,
inspect all hoses, clamps and connections for deterio-ration and leaks. Inspect radiator and heater core forleaks.
CS ENGINE 7 - 13
ENGINE (Continued)
Fig. 1 Temperature Gauge Indications
7 - 14 ENGINE CS
ENGINE (Continued)
COOLANT
DESCRIPTION - ENGINE COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOLBASE COOLANT AND IS HARMFUL IF SWAL-LOWED OR INHALED. IF SWALLOWED, DRINKTWO GLASSES OF WATER AND INDUCE VOMIT-ING. IF INHALED, MOVE TO FRESH AIR AREA.SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOTSTORE IN OPEN OR UNMARKED CONTAINERS.WASH SKIN AND CLOTHING THOROUGHLY AFTERCOMING IN CONTACT WITH ETHYLENE GLYCOL.KEEP OUT OF REACH OF CHILDREN. DISPOSE OFGLYCOL BASE COOLANT PROPERLY, CONTACTYOUR DEALER OR GOVERNMENT AGENCY FORLOCATION OF COLLECTION CENTER IN YOURAREA. DO NOT OPEN A COOLING SYSTEM WHENTHE ENGINE IS AT OPERATING TEMPERATURE ORHOT UNDER PRESSURE, PERSONAL INJURY CANRESULT. AVOID RADIATOR COOLING FAN WHENENGINE COMPARTMENT RELATED SERVICE ISPERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolantsis not recommended, as they provide less freezeprotection and less boiling protection.
The cooling system is designed around the coolant.The coolant must accept heat from engine metal, inthe cylinder head area near the exhaust valves andengine block. Then coolant carries the heat to theradiator where the tube/fin radiator can transfer theheat to the air.
The use of aluminum cylinder blocks, cylinderheads, and water pumps requires special corrosionprotection. Mopart Antifreeze/Coolant, 5Year/100,000 Mile Formula (MS-9769), or the equiva-lent ethylene glycol base coolant with hybrid organiccorrosion inhibitors (called HOAT, for Hybrid OrganicAdditive Technology) is recommended. This coolantoffers the best engine cooling without corrosion whenmixed with 50% Ethylene Glycol and 50% distilledwater to obtain a freeze point of -37°C (-35°F). If itloses color or becomes contaminated, drain, flush,and replace with fresh properly mixed coolant solu-tion.
The green coolant MUST NOT BE MIXED withthe orange or magenta coolants. When replacing cool-ant the complete system flush must be performedbefore using the replacement coolant.
CAUTION: Mopar T Antifreeze/Coolant, 5Year/100,000 Mile Formula (MS-9769) may not bemixed with any other type of antifreeze. Doing sowill reduce the corrosion protection and may resultin premature water pump seal failure. If non-HOATcoolant is introduced into the cooling system in anemergency, it should be replaced with the specifiedcoolant as soon as possible.
DIAGNOSIS AND TESTING - COOLANTCONCENTRATION TESTING
Coolant concentration should be checked when anyadditional coolant was added to system or after acoolant drain, flush and refill. The coolant mixtureoffers optimum engine cooling and protection againstcorrosion when mixed to a freeze point of -37°C(-34°F) to -46°C (-50°F). The use of a hydrometer or arefractometer can be used to test coolant concentra-tion.
A hydrometer will test the amount of glycol in amixture by measuring the specific gravity of the mix-ture. The higher the concentration of ethylene glycol,the larger the number of balls that will float, andhigher the freeze protection (up to a maximum of60% by volume glycol).
A refractometer (Special Tool 8286)(Refer to 7 -COOLING - SPECIAL TOOLS) will test the amountof glycol in a coolant mixture by measuring theamount a beam of light bends as it passes throughthe fluid.
Some coolant manufactures use other types of gly-cols into their coolant formulations. Propylene glycolis the most common new coolant. However, propyleneglycol based coolants do not provide the same freez-ing protection and corrosion protection and is not rec-ommended.
CAUTION: Do not mix types of coolant—corrosionprotection will be severely reduced.
STANDARD PROCEDURE - COOLANT SERVICEFor engine coolant recommended service schedule,
(Refer to LUBRICATION & MAINTENANCE/MAIN-TENANCE SCHEDULES - DESCRIPTION).
CS ENGINE 7 - 15
COOLANT RECOVERY PRESSCONTAINER
DESCRIPTIONThe coolant recovery/reserve system container is
mounted in the engine compartment. The containeris made of plastic.
OPERATIONThe coolant recovery system works with the pres-
sure cap to use thermal expansion and contraction ofthe coolant to keep the coolant free of trapped air.Provides a convenient and safe method for checkingcoolant level and adjusting level at atmospheric pres-sure without removing the pressure cap. It also pro-vides some reserve coolant to cover deaeration,evaporation, or boiling losses.
REMOVAL(1) Disconnect two recovery hoses from the coolant
recovery container (Fig. 2).(2) Remove the lower attaching nuts (Fig. 2).(3) Remove the upper attaching nut (Fig. 2).(4) Remove the recovery container.
INSTALLATION(1) Connect the recovery hose to container.(2) Position the recovery container on the frame
rail (Fig. 2).(3) Install the upper attaching screw and tighten
to 7 N·m (60 in. lbs.).(4) Raise the vehicle on hoist.
(5) Install the lower attaching screws and tightento 8.5 N·m (75 in. lbs.).
(6) Lower the vehicle.(7) Add coolant to container as necessary(Refer to
7 - COOLING - STANDARD PROCEDURE).
Fig. 2 COOLANT RECOVERY CONTAINER1 - UPPER RETAINING NUT2 - COOLANT RECOVERY CONTAINER3 - LOWER RETAINING NUTS4 - RECOVERY HOSE
7 - 16 ENGINE CS
RADIATOR FAN
OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE A/C PRESSURE TRANSAXLE OILTEMPERATURE
FanOperationSpeeds:
Initial Max Initial Max Initial Max
Fan On: 104°C(220°F)
110°C(230°F) FanSpeedDuty-Cycles(Ramps-up)from 50% to99%
1,724 Kpa(250 psi)
2,068 Kpa(300 psi) FanSpeedDuty-Cycles(Ramps-up)from 50% to99%
98°C (208°F) 109°C (228°F)Fan SpeedDuty Cycles(Ramps-up)from 50% to99%
Fan Off: 101°C(214°F)
Fan SpeedDuty-Cycles(Ramps-down) from99% to 50%
1,379 Kpa(200 psi)
Fan SpeedDuty-Cycles(Ramps-down) from99% to 50%
89°C (192°F) Fan SpeedDuty Cycles(Ramps-down)from 99% to50%
DIAGNOSIS AND TESTING - RADIATOR FAN MOTOR
RADIATOR FAN DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY RADIATOR FAN 1. Fan blade loose. 1. Replace fan assembly. (Refer to7 - COOLING/ENGINE/RADIATORFAN - REMOVAL)
2. Fan blade striking a surroundingobject.
2. Locate point of fan blade contactand repair as necessary.
3. Air obstructions at radiator or A/Ccondenser.
3. Remove obstructions and/orclean debris.
4. Electric fan motor defective. 4. Replace fan assembly. (Refer to7 - COOLING/ENGINE/RADIATORFAN - REMOVAL)
ELECTRIC FAN MOTOR DOESNOT OPERATE
1. Fan relay, powertrain controlmodule (PCM), coolant temperaturesensor, or wiring defective.
1. (Refer to Appropriate DiagnosticInformation) Repair as necessary.
2. Defective A/C pressuretransducer.
2. (Refer to Appropriate DiagnosticInformation) Repair as necessary.
ELECTRIC RADIATOR FANOPERATES ALL THE TIME
1. Fan relay, powertrain controlmodule (PCM), coolant temperaturesensor or wiring defective.
1. (Refer to Appropriate DiagnosticInformation) Repair as necessary.
2. Check for low coolant level. 2. Add coolant as necessary.
3. Defective A/C pressuretransducer.
3. (Refer to Appropriate DiagnosticInformation) Repair as necessary.
CS ENGINE 7 - 17
REMOVALThere are no repairs to be made to the fan or
shroud assembly. If the fan is warped, cracked, orotherwise damaged, it must be replaced as an assem-bly (Fig. 3).
(1) Remove the fron fascia (Refer to 13 - FRAME& BUMPERS/BUMPERS/FRONT FASCIA - REMOV-AL).
(2) Disconnect the radiator fan electrical connec-tors.
(3) Remove radiator fan(s) retaining screw (Fig. 3).(4) Remove the radiator fan(s) by lifting upward to
release from mounts.
INSTALLATION(1) Install the radiator fan(s) into mounts and
attaching clips on the radiator.(2) Install radiator fan(s) attaching screws (Fig. 3).
Tighten to 5 N·m (45 in. lbs.).(3) Connect the radiator fan(s) electrical connec-
tors.(4) Install the front fascia (Refer to 13 - FRAME &
BUMPERS/BUMPERS/FRONT FASCIA - INSTAL-LATION).
(5) Install the upper radiator mounts to the cross-member bolts, if removed. Tighten to 8 N·m (70 in.lbs.).
ENGINE BLOCK HEATER
DESCRIPTIONThe engine block heater is available as an optional
accessory on all models. The heater is operated byordinary house current (110 Volt A.C.) through apower cord located behind the radiator grille. Thisprovides easier engine starting and faster warm-upwhen vehicle is operated in areas having extremelylow temperatures. The heater is mounted in a corehole (in place of a core hole plug) in the engine block,with the heating element immersed in coolant.
OPERATIONThe block heater element is submerged in the cool-
ing system’s coolant. When electrical power (110 voltA.C.) is applied to the element, it creates heat. Thisheat is transferred to the engine coolant. This pro-vides easier engine starting and faster warm-upwhen vehicle is operated in areas having extremelylow temperatures.
REMOVAL(1) Drain coolant from radiator and cylinder block
(Refer to 7 - COOLING - STANDARD PROCE-DURE).
(2) Disconnect the power cord plug from heater.(3) Loosen bolt. Remove the block heater assembly
(Fig. 4).
Fig. 3 RADIATOR FANS1 - RADIATOR2 - RADIATOR FAN - LEFT3 - RADIATOR FAN - RIGHT
Fig. 4 Block Heater1 - BLOCK HEATER12 - ELECTRICAL CONNECTOR2 - BOLT
7 - 18 ENGINE CS
RADIATOR FAN (Continued)
INSTALLATION(1) Clean block core hole and heater seat.(2) Insert heater assembly with element loop posi-
tioned upward.(3) With heater seated, tighten center screw
securely to assure a positive seal.(4) Install power cord plug to heater.(5) Fill cooling system with coolant to the proper
level (Refer to 7 - COOLING - STANDARD PROCE-DURE).
ENGINE COOLANT TEMPSENSOR
DESCRIPTIONThe engine coolant temperature sensor threads
into a coolant passage on lower intake manifold nearthe thermostat. New sensors have sealant applied tothe threads (Fig. 5).
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CANCAUSE INJURY BY SCALDING. COOLING SYSTEMMUST BE PARTIALLY DRAINED BEFORE REMOV-ING THE COOLANT TEMPERATURE SENSOR.
(1) Drain cooling system below engine coolant tem-perature sensor level (Refer to 7 - COOLING - STAN-DARD PROCEDURE).
(2) Disconnect negative cable from remote jumperterminal (Fig. 5)
(3) With the engine cold, disconnect coolant sensorelectrical connector.
(4) Remove sensor.
INSTALLATION(1) Install engine coolant temperature sensor (Fig.
5). Tighten sensor to 7 N·m (60 in. lbs.).(2) Connect electrical connector to sensor.(3) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
ENGINE COOLANTTHERMOSTAT
REMOVAL
WARNING: DO NOT REMOVE PRESSURE CAPWITH THE SYSTEM HOT AND UNDER PRESSUREBECAUSE SERIOUS BURNS FROM COOLANT CANOCCUR.
(1) Disconnect negative cable from remote jumperterminal.
(2) Drain cooling system (Refer to 7 - COOLING -STANDARD PROCEDURE).
(3) Raise vehicle on hoist.(4) Disconnect electrical connectors from engine oil
and power steering pressure switches.(5) Disconnect radiator and heater hoses from
thermostat housing.(6) Remove thermostat housing bolts (Fig. 6).(7) Remove housing, thermostat, and gasket.
NOTE: The OEM thermostat is staked in place at thefactory. To ensure proper seating of replacementthermostat, carefully remove the bulged metal fromthe thermostat housing using a suitable hand heldgrinder. It is not necessary to restake the replace-ment thermostat into the thermostat housing.
INSTALLATION
NOTE: The OEM thermostat is staked in place at thefactory. To ensure proper seating of replacementthermostat, carefully remove the bulged metal fromthe thermostat housing using a suitable hand heldgrinder. It is not necessary to restake the replace-ment thermostat into the thermostat housing.
(1) Clean gasket sealing surfaces.(2) Install thermostat and gasket into thermostat
housing. For ease of installation, install bolts inhousing for thermostat and gasket retention.
(3) Install thermostat and housing to cylinderblock (Fig. 6). Tighten bolts to 12 N·m (105 in. lbs.).
Fig. 5 ENGINE COOLANT TEMPERATURE SENSOR -3.5L
1 - CAMSHAFT POSITION SENSOR2 - ENGINE COOLANT TEMPERATURE SENSOR
CS ENGINE 7 - 19
ENGINE BLOCK HEATER (Continued)
(4) Connect heater and radiator hoses and installhose clamps.
(5) Connect electrical connectors to engine oil andpower steering pressure switches.
(6) Lower vehicle and connect negative cable toremote jumper terminal.
(7) Refill cooling system (Refer to 7 - COOLING -STANDARD PROCEDURE).
(8) Connect negative cable to remote jumper termi-nal.
HEATER SUPPLY TUBE
REMOVAL
WARNING: DO NOT REMOVE PRESSURE CAPWITH SYSTEM HOT AND UNDER PRESSUREBECAUSE SERIOUS BURNS FROM COOLANT CANOCCUR.
(1) Drain cooling system. (Refer to 7 - COOLING -STANDARD PROCEDURE).
(2) Remove upper and lower intake manifold(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-FOLD - REMOVAL).
(3) Position lower intake manifold upside down onbench and remove the tube retaining bolt (Fig. 7).
(4) Remove tube from manifold and discard O-ring.
INSTALLATION(1) Clean heater tube sealing surfaces.(2) Inspect heater tube O-ring. Replace as neces-
sary.(3) Lubricate O-ring with a silicone type grease
such as Mopart Dielectric Grease (Fig. 7).(4) Install O-ring on heater tube.(5) Install heater tube on manifold.(6) Install retaining bolts and tighten to 12 N·m
(105 in. lbs.).(7) Install lower and upper intake manifolds (Refer
to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD -INSTALLATION).
(8) Refill cooling system (Refer to 7 - COOLING -STANDARD PROCEDURE).
HOSE CLAMPS
DESCRIPTIONThe cooling system utilizes both worm drive and
spring type hose clamps. If a spring type clampreplacement is necessary, replace with the originalMopart equipment spring type clamp. To identifysize of spring hose clamps, the size in millimetershas been stamped on each clamp (Fig. 8).
Fig. 6 Thermostat and Housing - 3.5L Engines1 - THERMOSTAT HOUSING/COOLANT INLET2 - THERMOSTAT3 - GASKET Fig. 7 Heater Supply Tube - 3.5L
1 - COOLANT TEMPERATURE SENSOR2 - O-RING3 - BOLT4 - HEATER SUPPLY TUBE5 - BOLT
7 - 20 ENGINE CS
ENGINE COOLANT THERMOSTAT (Continued)
OPERATIONThe worm type hose clamp uses a specified torque
value to maintain proper tension on a hose connec-tion.
The spring type hose clamp applies constant ten-sion on a hose connection. To remove a spring typehose clamp, use Special Tool 6094 or equivalent, con-stant tension clamp pliers (Fig. 9) to compress thehose clamp.
RADIATOR
REMOVAL(1) Disconnect negative cable from battery.(2) Discardge the A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/REFRIG-ERANT - STANDARD PROCEDURE)
(3) Remove the fron fascia (Refer to 13 - FRAME &BUMPERS/BUMPERS/FRONT FASCIA - REMOVAL).
WARNING: DO NOT REMOVE THE CYLINDERBLOCK PLUG OR THE RADIATOR DRAINCOCKWITH THE SYSTEM HOT AND UNDER PRESSUREBECAUSE SERIOUS BURNS FROM COOLANT CANOCCUR.
(4) Drain the cooling system. (Refer to 7 - COOL-ING - STANDARD PROCEDURE).
(5) Disconnect the radiator fan electrical connec-tors.
(6) Disconnect coolant reserve/recovery hose.(7) Remove A/C lines (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/A/C CON-DENSER - REMOVAL).
(8) Remove the auxiliary transmission coolerhoses.
(9) Remove the pushpins and the upper radiatorseal.
(10) Remove the pushpins and the LH and RHradiator seal (Fig. 10).
(11) Remove the A/C condenser side brackets toradiator attaching screws (Fig. 12). Separate the con-denser from the radiator by lifting upward to disen-gage from lower mounts (Fig. 12). Allow thecondenser to rest in front of radiator.
(12) Remove the upper and lower radiator hoses.
Fig. 8 Spring Clamp Size Location1 - SPRING CLAMP SIZE LOCATION
Fig. 9 Hose Clamp Tool1 - HOSE CLAMP TOOL 60942 - HOSE CLAMP
Fig. 10 Radiator Seals1 - RH RADIATOR SEAL2. - PUSHPIN3 - UPPER RADIATOR SEAL
CS ENGINE 7 - 21
HOSE CLAMPS (Continued)
(13) Radiator can now be lifted free from enginecompartment. Care should be taken not to dam-age radiator cooling fins or water tubes duringremoval. (Fig. 11)
(14) Remove the auxiliary transmission from theradiator module.
(15) Remove the cooling fan assembly from theradiator module.
INSTALLATION(1) Install A/C condenser, (if removed)(Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/CCONDENSER - INSTALLATION).
(2) Install radiator fan assemble, if removed (Referto 7 - COOLING/ENGINE/RADIATOR FAN -INSTALLATION).
(3) Install auxiliary transmission cooler, ifremoved.
(4) Slide radiator down into position. Seat theradiator with the rubber isolators into the mountingholes provided, with a 10 lbs. force.
(5) Install mounting screws.(6) Connect the cooling fan electrical connector.(7) Install the radiator upper and lower hoses(8) In the LH and RH radiator seals.(9) Install the upper radiator seal.(10) Install the auxiliary transmission coole hoses.(11) Connect the coolant reserve/recovery hose.(12) Install the front fascia (Refer to 13 - FRAME
& BUMPERS/BUMPERS/FRONT FASCIA - INSTAL-LATION).
(13) Fill the cooling system. (Refer to 7 - COOL-ING - STANDARD PROCEDURE)
(14) Connect negative cable to battery.
RADIATOR DRAINCOCK
REMOVAL
WARNING: DO NOT REMOVE THE CYLINDERBLOCK PLUG OR THE RADIATOR DRAINCOCKWITH THE SYSTEM HOT AND UNDER PRESSUREBECAUSE SERIOUS BURNS FROM COOLANT CANOCCUR.
CAUTION: Use of pliers on draincock is not recom-mended. Damage may occur to part. Draincockshould not be removed unless leakage is observed.
(1) Drain the cooling system (Refer to 7 - COOL-ING - STANDARD PROCEDURE).
(2) Turn the draincock stem counterclockwise 180degrees to the 9:00 o’clock position.
(3) With the stem at the 9:00 o’clock position, pullthe draincock assembly from the radiator tank (Fig.13).
Fig. 11 Radiator Module1 - RADIATOR MODULE2 - AUXILIARY TRANSMISSION COOLER HOSES2 - AUXILIARY TRANSMISSION COOLER
Fig. 12 A/C CONDENSER TO RADIATOR1 - SCREW - A/C CONDENSER SIDE BRACKET TO RADIATOR2 - LOWER MOUNT3 - A/C CONDENSER
7 - 22 ENGINE CS
RADIATOR (Continued)
INSTALLATION(1) Inspect the draincock body and O-ring for dam-
age. Replace as necessary.(2) Position the draincock assembly horizontally to
the tank opening with the manufactures identifica-tion mark facing down.
(3) Push the draincock assembly into the tankopening while rotating clockwise until it snaps intoplace.
(4) Close the draincock stem by turning clockwiseuntil it stops at the horizontal position.
(5) Fill the cooling system (Refer to 7 - COOLING- STANDARD PROCEDURE).
PRESSURE CAP
DESCRIPTIONThe cooling system pressure cap is located on the
collant pressure container. The cap constructionincludes; stainless steel swivel top, rubber seals, andretainer, main spring, and a spring loaded valve (Fig.14).
OPERATIONThe cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a rangeof 97-124 kPa (14-18 psi).
The cooling system will operate at higher thanatmospheric pressure. The higher pressure raises thecoolant boiling point thus, allowing increased radia-tor cooling capacity.
There is also a vent valve in the center of the cap.This valve also opens when coolant is cooling andcontracting, allowing the coolant to return to coolingsystem from coolant reserve system tank by vacuumthrough a connecting hose. If valve is stuck shut,
or the coolant recovery hose is pinched, theradiator hoses will be collapsed on cool down.Clean the vent valve (Fig. 14) and inspect cool-ant recovery hose routing, to ensure propersealing when boiling point is reached.
The gasket in the cap seals the filler neck, so thatvacuum can be maintained, allowing coolant to bedrawn back into the radiator from the reserve tank.If the gasket is dirty or damaged, a vacuummay not be achieved, resulting is loss of coolantand eventual overheating due to low coolantlevel in radiator and engine.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEMPRESSURE CAP TESTING
Dip the pressure cap in water. Clean any depositsoff the vent valve or its seat and apply cap to end ofthe Pressure Cap Test Adaptor that is included withthe Cooling System Tester 7700 (Fig. 15). Workingthe plunger, bring the pressure to 104 kPa (15 psi) onthe gauge. If the pressure cap fails to hold pressureof at least 97 kPa (14 psi), replace the pressure cap.
CAUTION: The Cooling System Tester Tool is verysensitive to small air leaks that will not cause cool-ing system problems. A pressure cap that does nothave a history of coolant loss should not bereplaced just because it leaks slowly when testedwith this tool. Add water to the tool. Turn toolupside down and recheck pressure cap to confirmthat cap is bad.
Fig. 13 Draincock1 - DRAINCOCK ASSEMBLY
Fig. 14 Cooling System Pressure Cap Filler Neck1 - OVERFLOW NIPPLE2 - MAIN SPRING3 - GASKET RETAINER4 - STAINLESS-STEEL SWIVEL TOP5 - RUBBER SEALS6 - VENT VALVE7 - COOLANT PRESSURE CONTAINER8 - FILLER NECK
CS ENGINE 7 - 23
RADIATOR DRAINCOCK (Continued)
If the pressure cap tests properly while positionedon Cooling System Tester (Fig. 15), but will not holdpressure or vacuum when positioned on the fillerneck. Inspect the filler neck and cap top gasket forirregularities that may prevent the cap from sealingproperly.
DIAGNOSIS AND TESTING - PRESSURE CAPTO FILLER NECK SEAL
The pressure cap upper gasket (seal) pressurerelief can be checked by removing the overflow hoseat the radiator filler neck nipple (Fig. 16). Attach theRadiator Pressure Tool to the filler neck nipple andpump air into the system. Pressure cap upper gasketshould relieve at 69-124 kPa (10-18 psi) and holdpressure at 55 kPa (8 psi) minimum.
WARNING: THE WARNING WORDS “DO NOT OPENHOT” ON THE PRESSURE CAP IS A SAFETY PRE-CAUTION. WHEN HOT, PRESSURE BUILDS UP INCOOLING SYSTEM. TO PREVENT SCALDING ORINJURY, THE RADIATOR CAP SHOULD NOT BEREMOVED WHILE THE SYSTEM IS HOT OR UNDERPRESSURE.
There is no need to remove the radiator cap at anytime except for the following purposes:
(1) Check and adjust coolant freeze point.(2) Refill system with new coolant.(3) Conducting service procedures.(4) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,WAIT 15 MINUTES BEFORE REMOVING CAP. THENPLACE A SHOP TOWEL OVER THE CAP AND WITH-OUT PUSHING DOWN ROTATE COUNTERCLOCK-WISE TO THE FIRST STOP. ALLOW FLUIDS TOESCAPE THROUGH THE OVERFLOW TUBE ANDWHEN THE SYSTEM STOPS PUSHING COOLANTAND STEAM INTO THE CRS TANK AND PRESSUREDROPS PUSH DOWN AND REMOVE THE CAP COM-PLETELY. SQUEEZING THE RADIATOR INLET HOSEWITH A SHOP TOWEL (TO CHECK PRESSURE)BEFORE AND AFTER TURNING TO THE FIRSTSTOP IS RECOMMENDED.
CLEANINGUse only a mild soap to clean the pressure cap.
INSPECTIONHold the cap in your hand, right side up (Fig. 17).
The vent valve at the bottom of the cap should benormally closed. The vent valve should open with aslight pull with your finger nail. Replace the pres-sure cap for any of the following:
• Rubber gasket has swollen, preventing the valvefrom opening, replace the cap.
• ANy light can be seen between the vent valveand the rubber gasket.Use only a replacement capthat has a spring to hold the valve shut.
• Gasket on the bottom of the cal shows noticablethinning.
• Cap has been through more then one engineoverheat.
RADIATOR FAN RELAY
DESCRIPTIONThe radiator fan relay is a solid state type and is
located on the back of the bumper beam. Refer toWIRING DIAGRAMS for a circuit schematic.
Fig. 15 Pressure Testing Radiator Cap1 - PRESSURE CAP2 - PRESSURE TESTER
Fig. 16 Cooling System Pressure Cap Filler Neck1 - OVERFLOW NIPPLE2 - MAIN SPRING3 - GASKET RETAINER4 - STAINLESS-STEEL SWIVEL TOP5 - RUBBER SEALS6 - VENT VALVE7 - COOLANT PRESSURE CONTAINER8 - FILLER NECK
7 - 24 ENGINE CS
PRESSURE CAP (Continued)
