3 CASE ADT 30 Ton Hydraulic Section.pdf

8/10/2019 3 CASE ADT 30 Ton Hydraulic Section.pdf

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HYDRAULIC

25 & 30 TON ARTICULATED DUMP TRUCKS

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HYDRAULIC SYSTEMHydraulic Circuits and Components

CONTENTSDescription PageSpecifications ....................................................1

Description ........................................................2Steering - dumping component location.........3Braking component location ........................5Component port identification7Troubleshooting ..............................................22Bleeding the hydraulic circuits ......................24Hydraulic system diagram ..........................25Checks and verification ................................. 33

SPECIFICATIONSMain hydraulic pump

Displacement .........................................................................117 cm/rev (7.14 in/rev)

Maximum delivery at engine full speed ...................................... 271 l/min (71.6 gal/min)Brake hydraulic pumpDisplacement ...........................................................................19.5 cm/rev (1.9 in/rev)Maximum delivery at engine full speed .........................................23 l/min (6.07 gal/min)Maximum pressure .............................................................................175 bar (2538 psi)Steering emergency electric-pump 25 TON TruckDisplacement ..........................................................................5.8 cm/rev (0.35 in/rev)Maximum delivery ........................................................................19 l/min (5.02 gal/min)Maximum pressure ............................................................................120 bar (1740 psi)DC power supply volt 24 VSteering emergency transmission driven pump 30 Ton Truck

Displacement ...........................................................................32 cm/rev (1.95 in/rev)Hoist cylinder rodsLength of Cylinder, extended 25 Ton Truck .................................2470 mm (97.24 in)Length of Cylinder, extended 30 Ton Truck ..................................1736 mm (68.34 in)Length of Cylinder, retracted..............................................................930 mm (36.61 in)Hoist control valveMain Relief valve pressure 25 Ton Truck .......................................140 bar (2030 psi)Main Relief valve pressure 30 Ton Truck .......................................160 bar (2320 psi)Circuit Relief valve retracting pressure ..................................................50 bar (725 psi)Circuit Relief valve extending pressure ..............................................225 bar (3263 psi)Power steering

Max. pressure ...................................................................................185 bar (2683 psi)Counterbalancing valvePressure setting .................................................................................100 bar (1450 psi)Flow amplifierSteering pressure relief pressure .......................................................185 bar (2683 psi)Circuit Relief valve relief pressure .....................................................240 bar (3481 psi)


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HYDRAULIC SYSTEM DESCRIPTION

The system is divided into three main hydraulic circuits, the steering, load dumping andbraking circuits. Each system operates with the same hydraulic fluid, coming from asingle reservoir that serves them all.

HYDRAULIC SYSTEM DESCRIPTION

1. Hydraulic oil reservoir2. Steering emergency pump3. Main hydraulic pump4. Brake hydraulic pump

5. Steering hydraulic circuit6. Load dumping hydraulic circuit7. Brake hydraulic circuit


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Steering Control System

On the Articulated Dump Trucks, a system for the delivery of high flow (flowamplification) to the steering cylinders is used. This system consists of a steeringcontrol valve, a Flow-amplifier and steering cylinders.

These systems with a steering control orbital valve and Flow-Amplifier also include a

priority flow divider valve in the Flow Amplifier which ensures that the steering takespriority. When the steering wheel is turned, the oil flow is divided in the Flow-Amplifier insuch a way as to ensure that the necessary oil flow is led to the steering system. Therest of the oil flow is available for the working hydraulics to raise and lower the dumpbody.

Steering Control System


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Steering Control Orbital Valve

The steering control orbital valve unit consists of a rotary valve and a rotary meter. Viaa steering column, the steering unit is connected to the steering wheel of the vehicle.Oil is supplied to the steering control orbital valve from the Flow Amplifier. When the

steering wheel is turned, oil is directed via the rotary valve and rotary meter to theorbital valve cylinder ports L or R, depending on the direction of the turn. The rotarymeter varies the oil flow to the Flow Amplifier in proportion to the angular rotation of thesteering wheel.

This steering system is of the load sensing design. In load sensing steering systemsboth the steering system and the working hydraulics can be supplied from just onepump. The load sensing steering unit has an extra connection for load sensing (LS), sothat a steering load pressure signal can be directed via the steering control orbital valveto a priority valve in the Flow Amplifier. The load sensing signal controls the oil flowfrom the priority valve to the steering cylinders. The LS connection is open to the

reservoir when the steering control orbital valve is in the neutral position.


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Steering Control Orbital Valve


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Steering Flow-Amplifier

On the Articulated Dump Trucks, a system for the delivery of high flow (flowamplification) to the steering cylinders is used. This system consists of a steeringcontrol orbital valve, and a Flow-amplifier.

The Flow-Amplifier contains a directional valve, a flow amplification stage, a priorityvalve, a pilot pressure relief valve and circuit relief and anti-cavitation valves. Inaddition, the Flow-Amplifier contains a backpressure valve to assure that oil is availablefor manual steering when the engine is not running. The Flow-Amplifier provides moreoil to the steering cylinders than would be possible to flow through the steering orbitalvalve. The Flow-Amplifier uses the lower flow through the orbital valve to provide acontrol flow to cause the amplifier spool of the Flow Amplifier to send about 8 timesmore oil to the CL or CR steering cylinder ports than what is going through the orbitalvalve. The amplified flow is proportional to the rate of the steering wheel rotation. If theoil flow from the pump fails, the Flow-Amplifier cuts off the amplification and manual

steering through the steering orbital valve is possible.


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Steering Flow-Amplifier

L Left Turn Signal from Orbital Valve LS Load sensing signal, same pressure as L or RCL Left Turn Pressure to Steering Cylinder HP Main flow from Pump

CR Right Turn Pressure to Steering Cylinder PP Pressure sense line of fluid flow to Orbital ValveR Right Turn Signal from Orbital Valve P Fluid supply flow to Orbital ValveEF Oil flow to Body Lifting Control ValveT Oil returning from the Orbital ValveHT Oil returned to the Reservoir


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Load Dumping Control Hydraulic System

25 TON TRUCK STEERING & DUMP CONTROL COMPONENT LOCATION

A. Emergency Steering Electric PumpB. Oil filter inside reservoir

C. Hydraulic oil reservoirD. Flow amplifierE. Load dumping control valveF. System pressure test portsG. High pressure oil filterH. Rear Cab Oil Porting Manifold

I. Main hydraulic pumpJ. Differential lock control solenoid valve

K. Power steering Orbital valveL. Hydraulic Oil CoolerM. Steering cylinderN. Hoist cylindersO. Rear chassis connection manifold (withcounter-balancing valve)


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30 TON TRUCK STEERING & DUMP CONTROL COMPONENT LOCATION

A.Auxiliary Steering By-pass valveB. Oil filter inside reservoirC. Hydraulic oil reservoirD. Flow amplifierE. Load dumping control valveF. System pressure test ports

G. High pressure oil filterH. Rear Cab Oil Porting ManifoldI. Main hydraulic pump

J. Differential lock control solenoid valveK. Power steering Orbital valveL. Hydraulic Oil CoolerM. Steering emergency pumpN. Transmission Differential locking valveO. Steering cylinder

P. Hoist cylindersQ. Rear chassis connection manifold (withcounter-balancing valve)R. Center Axle Differential Lock SolenoidValve

Rear Chassis 30 Ton Truck


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25 TON TRUCK BRAKE CIRCUIT COMPONENT LOCATION

P. Brake pumpQ. Oil filter (brake system)R. Service Brake Accumulators

S. Parking brake solenoid valveT.Accumulator charging valveU. Brake control valve


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A. 25 TON TRUCK EMERGENCY STEERING ELECTRIC PUMP

1. Oil inlet pipe from Tee at brake pump 2. outlet pipe to one-way check valve

A. 30 TON TRUCK AUXILIARY STEERING BY-PASS VALVELocated inside the right rear corner of the front chassis. Emergency steering pumpmounted to the rear of the transmission.

B. OIL FILTER INSIDE RESERVOIR

1. Oil intake pipe2. Hydraulic Reservoir Oil Fill

3. Pump Suction filtering element4. Hydraulic oil reservoir


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C. HYDRAULIC RESERVOIR

1. Filler cap2. Oil level gauge

3. Inspection cover


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D. FLOW AMPLIFIER

1. Inlet from one-way check valve (HP)2. Oil supply to Load dumping controlvalve (EF Port)3. Steering load sense pressure port (LS)4. RH steering control (R) to steeringcylinders5. Steering return (T) from orbital valve

6. LH steering (L) from orbital valve7. Return to reservoir (HT)8. RH steering (R) from orbital valve9. Oil supply (P) to orbital valve10. LH steering control (L) to steeringcylinders


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E. LOAD DUMPING CONTROL VALVE

1. Load dumping control manual lever2. Inlet from flow amplifier (to P Port)3. Body Raise control flow4. Supply to axle differential lock solenoidvalve (located inside left front accesscover on 30 Ton Truck & near flowamplifier on 25 Ton Truck)

5. Body lower control flow6. To Pressure test port connection7. Return to oil cooler and reservoir


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G. 25 TON TRUCK HIGH PRESSURE OIL FILTER

G. 30 TON TRUCK HIGH PRESSURE OIL FILTER

1. Inlet pipe from main pump

2. Inlet pipe from emergency Steeringpump3. Delivery pipe to flow amplifier (HP Port)

4. Pressure switch for emergency steering

5. Check valve from filter to flow amplifier6. High pressure oil filter


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H. REAR CAB OIL PORTING MANIFOLD

1. Body lowering from control valve (BPort)2. LH steering control3. RH steering control4. Center axle Differential lock control5. Parking brake control6. Rear service brake control

7. Body raising from control valve (A Port)8. Transmission pressure test port (30Ton Truck only)9. Transmission pressure test port (30Ton Truck only)10. Electrical Harness connector

I. MAIN HYDRAULIC PUMP

1. Inlet pipe from reservoir2. Outlet pipe to high pressure filter

3. Supply pipe to emergency steeringpump on 30 Ton Truck


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J. 30 TON TRUCK TRANSMISSION DIFFERENTIAL LOCK CONTROL VALVE


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K. POWER STEERING ORBITAL VALVE

1. Load sensing line to flow amplifier (LS)2. RH steering control to flow amplifier (R)3. Steering control inlet (P) from flowamplifier

4. Return pipe to flow amplifier (T)5. LH steering control to flow amplifier (L)

L. HYDRAULIC OIL COOLER

1. Oil return pipe to reservoir2. Inlet pipe from load dumping controlvalve (T Port)

3. Hydraulic Oil Cooler


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M. 30 TON TRUCK EMERGENCY STEERING PUMP

1. Emergency Steering Pump2. Inlet from Hydraulic Reservoir

3. Pump outlet to emergency Steeringsolenoid control valve

N. CENTER AXLE DIFFERENTIAL LOCK CONTROL SOLENOID VALVE

1. Oil return pipe to reservoir (T Port)2. Transmission differential lock control(A2 Port), Not used on 30 Ton Truck3. Center tandem differential lock control(A1 Port)4. Supply line from load dumping controlvalve (P Port)

5. To Center Axle Differential LockPressure test Coupler (MA Port)6. Center Axle Differential Lock PressureRegulator7. Center Axle Differential Lock ControlSolenoid8. Trans. Diff. Lock Sol., Not on 30 Ton


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O. STEERING CYLINDER

1. LH steering control pipe 2. RH steering control pipe

P. HOIST CYLINDER

1. Body raise control pipe 2. Body lower control pipe


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Q. REAR CHASSIS CONNECTION MANIFOLD ASSEMBLY

1. Body Raise control pipe2. Body Raise RH cylinder control pipe3. Body Raise LH cylinder control pipe4. Body Lowering RH cylinder control pipe5. Body Lowering LH cylinder control pipe6. LH steering control pipe

7. RH steering control pipe8. Body Lower control pipe9. Differential lock control pipe10. Parking brake control pipe11. Rear Axle Service brake control pipe12.Dump Body Counterbalance Valve


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R. BRAKE PUMP

1. Oil Supply to steering emergency pump Not used on 30 Ton Truck2. Oil inlet pipe from reservoir

3. Oil return pipe to reservoir4. Delivery pipe to high pressure brakefilter

S. BRAKE OIL FILTER

1. Starter Unloading Solenoid valve2. Delivery pipe to accumulator rechargingvalve

3. Return pipe to reservoir4. Inlet pipe from pump5.Brake Filter


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T. ACCUMULATOR RECHARGING VALVE

1. Supply line from brake filter on 30 Ton,Supply line from starter unloading solenoidvalve on 25 Ton Truck2. Front brake accumulator S1 supply line3. Rear brake accumulator S2 supply line

4. Parking brake accumulator S3 supplyline5. Oil return pipe to reservoir (main circuit)6. Oil discharge pipe to reservoir (drivecircuit)7. Low brake pressure switch


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U. 25 TON TRUCK ACCUMULATORS

U. 30 TON TRUCK ACCUMULATORS

1. Supply line from valve A1 ofaccumulator recharging valve2. Supply line to valve P (upper) of service

brake pressure control valve3. Supply line from valve A 2ofaccumulator recharging valve

4. Supply line to valve P (lower) of servicebrake pressure control valve5. Supply line from one-way check valve

on recharging valve to park brake accum.6. Supply line to parking brake controlsolenoid valve


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V. PARKING BRAKE CONTROL SOLENOID VALVE

1. Supply line from park brake accumulator

2. Parking brake control pipe3. Return pipe to reservoir

4. Park Brake Solenoid Control valve5. Park Brake Pressure Switch6.Park Brake Solenoids

W. SERVICE BRAKE CONTROL VALVE

1. Supply line from recharging valve (A 1)2. Supply line from recharging valve (A 2)3. Front axle brake control pipe4. Rear axles brake control pipe

5. Front brake return pipe to reservoir6. Rear brakes return pipe to reservoir7. Brake Light Pressure switch


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TROUBLESHOOTING

PROBLEM POSSIBLE CAUSES REMEDY

Slow hydraulic functions Oil level low

2. Oil cold

3. Oil not correct

4. Engine speed too low5. Pump worn6. Pump intake pipe

crimped

7. Suction filter in reservoirrestricted

1. Fill the reservoir to thefull level2. Wait a few minutes withthe engine running beforeusing the vehicle3. The oil used is notsuitable. Drain the reservoirand use the correct type4. Increase engine rpm5. Replace the pump6. Check condition of tubes

and replace them in theevent of damage and/orcrimping. Do not repair7. Clean or replace thesuction screen

Hydraulic system oiloverheats

Oil not correct

2. Air leakage into pumpintake pipe

3. Oil level low

4. Filters restricted5. Pump worn6. Oil cooler obstructed

7. Pressure relief valve

8. Contaminated oil

9. Hydraulic componentsnot adjusted correctly

1. The oil used is notsuitable. Drain the reservoirand use the correct type2. Check condition of tubesand replace them in theevent of damage and/or

crimping. Do not repair3. Fill the reservoir to theindicated level4. Replace with new filters5. Replace the pump6. Clean and straightenfins, if bent7. Check operation of valveand replace it, if required8. Drain the reservoir anduse the correct type of oil

9. Check correctadjustment of hydrauliccomponents


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BLEEDING THE HYDRAULIC CIRCUITS

NOTE: The vehicle is equipped with asingle hydraulic system split into threecircuits: braking circuit; steering circuit;and load dumping circuit. Bleed each of

the three circuits separately.BRAKING CIRCUIT1. Press the brake pedal fully and hold itpressed down.2. Remove the dust cap, then fit atransparent tube on the bleeder (1).Submerge one end of the tube in a bowlcontaining oil.3. Loosen the valve, letting out the oil andthe air bubbles. Close it after a fewseconds.

NOTE: Close the valve if the end of theclear tube is not submerged.4. Fully release the brake pedal.5. Repeat the operation until oil withoutbubbles comes out of the bleeder.6. Close the bleeder.7. Fit the cap and repeat the operation onthe other braking units of the vehicle.7. At the end of the operation, check the oillevel in the reservoir and add more ifrequired.

STEERING CIRCUIT1. Start the engine, steer slowly and fullyto the right and then to the left.2. Repeat the operation a few times toeliminate the air bubbles in the circuit.3. At the end of the operation, check the oillevel in the reservoir and add more ifrequired.LOAD DUMPING CIRCUIT1. Start the engine and tip the bucket to fillthe circuit.

2. Bring the bucket back to home position.3. Repeat the operation several times toeliminate the air in the cylinders.4. At the end of the operation, check the oillevel in the reservoir and add more, ifrequired.


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25 TON TRUCK HYDRAULIC SYSTEM DIAGRAM

1. Emergency steering pump (19 L/min - 24V DC) (5 gal/min - 24V DC)2. Main hydraulic pump (117 cm3/rev) (7.13 in3/rev)3. Hydraulic brake pump (19.5 cm3/rev - 175 bar) (1.18 in3/rev - 2539 psi)4. Steering Orbital valve5. Flow amplifier

6. Load dumping valve7. Counterbalancing valve8. Parking brake control valve9. Differential Lock control valve10. Intake oil filter (125 )11.Accumulator recharge valve12. Service brake pressure control valve13. Hydraulic oil heat exchanger14. Pressurized filter (25 )15. Steering flow check valve17. Emergency steering pressure switch

18A. Load dumping control hydraulic pressure test point A18B. Steering control hydraulic pressure test point B18C. Differential Lock control hydraulic pressure test point C18E. Service Brake pressure test point E (At manifold at front of rear chassis)19. Steering cylinders20. Hoist cylinders21. Hydraulic accumulators (1.4 liters - 65 bar) (1.5 qt. - 942 psi)22. Park Brake check valve23. Service brake accumulator pressure switch (125 Bar 1813 psi)24. Brake stop light pressure switch (3 Bar 44 psi)26. Parking brake light switch

28. Brake pressure filter29. Brake filter restriction indicator switch30. Center axle differential Lock cylinder31. ZF Transmission Differential Lock shift cylinder32. Parking brake calipers33. Front axle brake calipers34. Rear axle brake calipers35. Center axle brake calipers36. Hydraulic oil cooler bypass restrictor37. Starter unloading solenoid valve (Brake Circuit)38. Rear cab oil porting manifold

39. Rear chassis connection manifold assembly


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25 & 30 TON ARTICULATED DUMP TRUCKS33

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30 TON TRUCK HYDRAULIC SYSTEM DIAGRAM1. Emergency steering pump (32 cm3/rev) (1.95 in3/rev)2. Main hydraulic pump (117 cm3/rev) (7.13 in3/rev)3. Hydraulic brake pump (19.5 cm3/rev - 175 bar) (1.18 in3/rev - 2539 psi)4. Steering Orbital valve5. Flow amplifier6. Load dumping valve7. Counterbalancing valve8. Parking brake control valve9. Center axle differential Lock control valve10. Intake oil filter (125 )11.Accumulator recharge valve12. Service brake pressure control valve13. Hydraulic oil heat exchanger14. Pressurized filter (25 )15. Steering flow check valve16. Emergency steering flow check valve17. Emergency steering pressure switch18A. Load dumping control hydraulic pressure test point A18B. Steering control hydraulic pressure test point B18C. Center axle Differential Lock control hydraulic pressure test point C18D. ZF Transmission Differential Lock control hydraulic pressure test point D18E. Service Brake pressure test point E (At manifold at front of rear chassis)19. Steering cylinders20. Hoist cylinders21. Hydraulic accumulators (1.4 liters - 65 bar) (1.5 qt. - 942 psi)22. Park Brake check valve

23. Service brake accumulator pressure switch (125 Bar 1813 psi)24. Brake stop light pressure switch (3 Bar 44 psi)25. Emergency steering control solenoid valve26. Parking brake light switch27. ZF Transmission Differential Lock control valve28. Brake pressure filter29. Brake filter restriction indicator switch30. Center axle differential Lock cylinder31. ZF Transmission Differential Lock shift cylinder32. Parking brake calipers33. Front axle brake calipers

34. Rear axle brake calipers35. Center axle brake calipers36. Hydraulic oil cooler bypass restrictor38. Rear cab oil porting manifold39. Rear chassis connection manifold assembly


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CHECKS AND VERIFICATION

HYDRAULIC PRESSURE TEST POINTSA. Load dumping Valve pressure test pointB. Steering pressure test pointC. Center Axle Differential Lock pressuretest pointD. Transmission Differential Lock pressuretest point on 30 Ton Truck Centralgreasing point for front chassis on 25 TonTruck

LOAD DUMPING VALVE PRESSURETEST POINT (A)

A hex wrench is used to adjust the mainpressure.1. Position the vehicle on a solid, level,surface with the engine running.2. Raise the dump body to its full extent.3. Connect a suitable pressure gauge tothe load dumping valve system test point(A).4. With the body raised to full extent and

control lever operated, bring the engine tofull speed. The pressure gauge shouldshow 1605 bar (2248 to 2393 psi).IMPORTANT: The pressure must neverexceed 165 bar (2393 psi) in all conditions.5. Remove the external plug and insert ahex wrench (1) into the adjustment plug onthe main valve block. To increasepressure, turn adjustment deviceclockwise. To decrease pressure, turnadjustment device counterclockwise.


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CHECKS AND VERIFICATION (continued)STEERING PRESSURE TEST POINT (B)1. Position the vehicle on a solid, levelsurface with the engine running.2. Connect a suitable pressure gauge tothe steering pressure test point (B).3. Turn the steering wheel to the left untilyou reach full lock and maintain full lockuntil the adjustment is complete.4. With the steering wheel still at full lock,bring the engine to full speed. Thepressure gauge should show 185 bar(2684 psi).5. The steering pressure adjustmentdevice is located on the flow amplifier (2).You are advised not to change the originalsetting. Requires a 5 mm hex wrench toadjust.CENTER AXLE DIFFERENTIAL LOCKPRESSURE TEST POINT (C)1. Position the vehicle on a solid, levelsurface with the engine running.2. Connect a suitable pressure gauge tothe center axle differential lock pressuretest point (C). The pressure gauge shouldshow a value in the range of 5 to 8 bar (72

to 116 psi).3. The adjustment device is located on thereduction valve (3) situated near the flowamplifier on the 25 Ton Truck and insidethe left front access cover on the NA 30Ton TruckIMPORTANT: The pressure must notexceed 8 bar (116 psi). This is themaximum required pressure. Highervalues could damage the cylinder.


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3 CASE ADT 30 Ton Hydraulic Section.pdf