Challenger 65E, Challenger 75E, Challenger 85E and Challenger 95E Agricultural Tractors Implement, Steering and Brake Hydraulic Systems Caterpillar

Troubleshooting for the Implement Hydraulic System

Problem List

• "The temperature of the hydraulic oil in the tank is too high."

• "The implement hydraulic pump makes unusual noises."

• "There is a large amount of air in the oil."

• "The pump pressure is too low."

• "The pump pressure is too high."

• "There is a pause before pressure is achieved in all the circuits."

• "The signal pressure is not zero when all of the valves are in the HOLD position."

• "Any implement moves when the control lever is in the HOLD position."

• "The hitch relief valve is too noisy."

• "The hitch drifts too much or the implement drifts too much."

• "The implement falls slightly when the implement is moving from a partially raised position to a fully raised position."

• "The cycle times are too slow for all implements."

• "The cycle time is too slow for an implement."

• "The cycle time is too fast for an implement."

• "The implement control valve does not return to the HOLD position when the hydraulic cylinders reach the end of the stroke."

• "The hitch moves slowly or the hitch does not move."

• "The hitch moves when the control lever has not been moved."

• "The hitch moves too fast."

• "The oil from the hydraulic system is being transferred into the transmission."

Probable Causes

The temperature of the hydraulic oil in the tank is too high.

1. Check the techniques of the operator. The load on the system may be too high.

   1. Change the operating techniques in order to reduce the load on the system.

2. Check the hydraulic oil tank level. The level may be too low.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

   2. Check for oil aeration by taking an oil sample. If aeration is found, see "There is a large amount of air in the oil".

3. The outside air temperature may be too hot.

   1. Change the operating techniques in order to reduce the load on the system.

4. Check the actual temperature of the oil.

   1. Insert a thermometer into the oil filler tube.

   2. If the temperature is below 82 °C (180 °F), there is an electrical problem with the temperature sensing system. Refer to Troubleshooting, RENR1803, "Electronic System".

5. Verify that the pump proceeds to low pressure standby when the implements and the hitch are not being operated.

   1. Perform the low pressure standby test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".
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   Illustration 1	g00566981
   Earlier compensator valve (1) Flow compensator spool

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   Illustration 2	g00513202
   Later compensator valve (1) Flow compensator spool (2) Orifice

   2. If the pump does not proceed to low pressure standby, make sure that flow compensator spool (1) moves freely inside the compensator valve. For the later version of the compensator valve, make sure that orifice (2) is free of debris.

   3. If necessary, repair the failure.

6. Make sure that the correct viscosity of oil is in the system.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

7. Verify that the pressure compensator spool valve opens at the correct oil pressure.

   1. Perform the high pressure stall test for the implement pump. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

8. Check for pump wear.

   1. Perform the pump efficiency check for the implement hydraulic pump. Refer to Systems Operation/Testing and Adjusting, "Pump Efficiency Check".

9. Check for a restriction in an oil passage.

   1. Determine the cause. If necessary, repair the machine.

10. Determine if the oil cooler bypass valve is stuck open.

    1. Determine the cause. If necessary, repair the oil cooler bypass valve.

11. Check for a blockage in the oil cooler.

    1. Determine the cause. If necessary, repair the machine.

12. Make sure that the multifunction valves are adjusted correctly.

    1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

13. Make sure that the charge relief valve is adjusted correctly.

    1. Perform the pressure test for the charge oil of the steering system. Refer to Systems Operation/Testing and Adjusting, "Steering System Charge Oil Pressure Test".

14. Check the steering pump for excessive wear.

The implement hydraulic pump makes unusual noises.

1. Make sure that the correct viscosity of oil is in the system.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

2. Determine if the hitch relief valve opens at low oil pressure.

   1. Adjust the hitch relief valve. Refer to Systems Operation/Testing and Adjusting, "Hitch Valve Adjustment".

3. Check for a loose connection of the oil line on the inlet side of the pump. Check for aeration of the oil.

   1. Tighten the connection, if necessary.

4. Check for pump wear.

   1. Perform the pump efficiency check for the implement hydraulic pump. Refer to Systems Operation/Testing and Adjusting, "Pump Efficiency Check".

There is a large amount of air in the oil.

1. Check for a leak in the oil line between the tank and the pump.

   1. Repair the leak, if necessary.

2. The air was not correctly purged from the hydraulic system after assembly, inspection or testing.

   1. Cycle the system in order to purge the air from the hydraulic system.

3. Determine if the hitch relief valve opens at low oil pressure.

   1. Adjust the hitch relief valve. Refer to Systems Operation/Testing and Adjusting, "Hitch Valve Adjustment".

4. Check for leakage around the seals in the hydraulic cylinders.

   1. If necessary, repair the seals.

The pump pressure is too low.

1. Determine if the flow compensator spool is adjusted correctly.

   1. Perform the Margin Pressure Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Test".

2. Make sure that the pressure compensator spool is adjusted correctly.

   1. Perform the High Pressure Stall Test on the implement pump. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Test".

3. There is a leak in the signal network.

   1. Perform the Resolver Network Check.

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Illustration 3	g00567113
Earlier compensator valve (2) Flow spool spring

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Illustration 4	g00513198
Later compensator valve (3) Flow spool spring

4. For the earlier version, inspect flow spool spring (2) and verify that the spring is not broken. For the later version, inspect flow spool spring (3) and verify that the spring is not broken.

5. Check for pump wear.

   1. Refer to Systems Operation/Testing and Adjusting, "Pump Efficiency Check".

6. Ensure that the swashplate is not blocked and ensure that the actuator spring is not broken.

   1. Repair the pump, if necessary.

The pump pressure is too high.

1. Determine if the flow compensator spool in the compensator valve is adjusted correctly.

   1. Perform the Margin Pressure Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Test".

2. Make sure that the pressure compensator spool is adjusted correctly.

   1. Perform the High Pressure Stall Test on the implement pump. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Test".

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Illustration 5	g00566981
Earlier compensator valve (1) Flow compensator spool

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Illustration 6	g00513202
Later compensator valve (1) Flow compensator spool (2) Orifice

3. Make sure that flow compensator spool (1) moves freely.

   1. Repair the compensator valve, if necessary.

4. For the later compensator valve, make sure that orifice (2) is free of debris.

5. Make sure that the pump is destroking. Ensure that the swashplate is not blocked and ensure that the actuator piston is not stuck.

   1. Repair the pump, if necessary.

There is a pause before pressure is achieved in all the circuits.

1. There may be air in the signal network.

   1. Purge the air from the hydraulic system by cycling the system several times.

2. Make sure that the flow compensator spool in the compensator valve is adjusted correctly.

   1. Perform the Margin Pressure Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Test".

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Illustration 7	g00566981
Earlier compensator valve (1) Flow compensator spool

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Illustration 8	g00513202
Later compensator valve (1) Flow compensator spool (2) Orifice

3. Make sure that flow compensator spool (1) moves freely.

   1. Repair the compensator valve, if necessary.

4. For the later compensator valve, make sure that orifice (2) is free of debris.

The signal pressure is not zero when all of the valves are in the HOLD position.

1. Make sure that all controls are in the HOLD position.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

2. Make sure that the signal network is connected to the tank.

   1. Verify that all of the lines are connected properly.

Any implement moves when the control lever is in the HOLD position.

1. Check for a leak in a connection between the implement control valve and the cylinders.

   1. Repair the connection, if necessary.

2. Check the implement control valve and the valve spool for excessive wear.

   1. Repair the valve, if necessary.

3. Check the piston seal in the hydraulic cylinder for excessive wear.

   1. Repair the piston seal, if necessary.

The hitch relief valve is too noisy.

1. Verify that the hitch relief valve is adjusted correctly.

   1. Adjust the hitch relief valve. Refer to Systems Operation/Testing and Adjusting, "Hitch Valve Adjustment".

2. Make sure that the pressure compensator spool in the compensator valve is adjusted correctly.

   1. Perform the High Pressure Stall Test on the implement hydraulic pump. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

   2. Repair the compensator valve, if necessary.

3. Make sure that the springs in the hitch relief valve have not failed.

   1. Replace the springs, if necessary.

The hitch drifts too much or the implement drifts too much.

1. Check for leakage around the piston seals in the hydraulic cylinders. Also, check for leakage around the piston seals in the implement cylinders.

   1. Repair the piston seals, if necessary.

2. Check the setting of the hitch relief valve.

   1. Adjust the relief valve, if necessary. Refer to Systems Operation/Testing and Adjusting, "Hitch Valve Adjustment".

3. Make sure that the spool in the control valve is centered correctly.

   1. Inspect the control valve for a broken spring.

   2. Make sure that the control spool moves freely.

   3. Repair the control valve, if necessary.

4. Check for leakage around the seals of the hitch relief valve.

   1. Repair the seals, if necessary.

5. Check for excessive wear on the control spool.

   1. Replace the spool, if necessary.

6. Make sure that the hitch relief valve is not loose.

   1. Tighten the hitch relief valve, if necessary.

The implement falls slightly when the implement is moving from a partially raised position to a fully raised position.

1. There may be air in the signal network.

   1. Purge the air from the implement hydraulic system by cycling the system several times.

2. Make sure that the flow compensator spool in the compensator valve is adjusted correctly.

   1. Perform the Margin Pressure Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".
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   Illustration 9	g00567414
   Earlier compensator valve (3) Spring for flow compensator spool (4) Spring for pressure compensator spool

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   Illustration 10	g00573630
   Later compensator valve (3) Spring for flow compensator spool (4) Spring for pressure compensator spool

   2. Inspect spring (3) and verify that the spring is not broken.

3. Make sure that the pressure compensator spool is operating correctly.

   1. Perform the High Pressure Stall Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

   2. Replace spring (4) if the pressure compensator spool cannot be adjusted correctly.

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Illustration 11	g00567467
(5) Flow control springs

4. Make sure that the springs (5) for the flow control spool (compensator) in the implement control valve are not broken.

   1. Replace the springs, if necessary.

5. Make sure that the signal passages in the main stem of the control valve are not blocked.

   1. Repair the control valve, if necessary.

6. Check the control valve for foreign material.

   1. Clean the control valve, if necessary.

The cycle times are too slow for all implements.

1. Make sure that the flow control knobs are adjusted correctly.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

2. Make sure that the flow compensator spool is adjusted correctly.

   1. Perform the Margin Pressure Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".
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   Illustration 12	g00567414
   Earlier compensator valve (3) Spring for flow compensator spool (4) Spring for pressure compensator spool

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   Illustration 13	g00573630
   Later compensator valve (3) Spring for flow compensator spool (4) Spring for pressure compensator spool

   2. Inspect spring (3) and verify that the spring is not broken.

3. Make sure that the pressure compensator spool is adjusted correctly.

   1. Perform the High Pressure Stall Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

   2. Replace spring (4) if the pressure compensator spool cannot be adjusted correctly.

4. Check for blockage in the signal network. Check for leakage in the signal network.

   1. Perform the resolver network check.

   2. Repair the signal network, if necessary.

5. Make sure that the pump fully strokes. Ensure that the actuator piston moves freely and ensure that the swashplate is not blocked.

   1. Repair the pump, if necessary.

The cycle time is too slow for an implement.

1. Make sure that the flow control knobs are adjusted correctly.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

2. Make sure that the implement valve cable is adjusted correctly.

   1. Refer to Specifications, RENR1740, "Implement Valve Cable Adjustment".

3. Make sure that the signal that is flowing to the compensator valve is not blocked.

   1. Perform the Margin Pressure Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

   2. If necessary, adjust the flow compensator spool in order to set the correct margin pressure. If the correct margin pressure cannot be achieved, there may be blockage in the signal network.

   3. Repair the signal network, if necessary.

4. Check for leakage around the piston seals of the hydraulic cylinders.

   1. Repair the piston seals, if necessary.

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Illustration 14	g00567467
(5) Flow control spring

5. Check flow control spring (5) in the implement control valve.

   1. Replace the spring, if necessary.

6. Make sure that the pump fully strokes. Ensure that the actuator piston moves freely and ensure that the swashplate is not blocked.

   1. Repair the pump, if necessary.

The cycle time is too fast for an implement.

1. Verify the operation of the flow control spool in the implement control valve.

   1. Inspect the flow control spool for missing parts or damaged parts.

   2. Clean the flow control spool. Dirt in the hydraulic oil may cause the spool to bind.

The implement control valve does not return to the HOLD position when the hydraulic cylinders reach the end of the stroke.

1. Make sure that the detent kickout pressure is adjusted correctly.

   1. Test the detent kickout pressure. Refer to Systems Operation/Testing and Adjusting, "Detent Kickout Pressure Tests".

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Illustration 15	g00567568
(6) Spring (7) Spring

2. Inspect springs (6) and (7) in the mechanism for the kickout of the detent.

   1. Repair the mechanism, if necessary.

The hitch moves slowly or the hitch does not move.

1. Verify that there is enough weight on the hitch.

   1. Add weight to the hitch in order to increase the rate of lowering.

2. The adjustment for manual lowering is set incorrectly.

   1. Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Adjustment".

3. Determine if the problem is electrical or hydraulic.

   1. Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Adjustment". Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Troubleshooting".

4. Check for dirt and check for debris in the pilot valve.

   1. Repair the pilot valve, if necessary.

5. Make sure that the implement hydraulic system is operating correctly.

   1. If necessary, perform the High Pressure Stall Test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

6. Make sure that the charge oil pressure for the steering hydraulic system is correct.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering System Charge Oil Pressure Test".

The hitch moves when the control lever has not been moved.

Note: When you are using the draft mode of operation for the three-point hitch, this may be part of the normal operation. Refer to Systems Operation/Testing and Adjusting, "Electronic Position Control System".

1. Check for a leak in the connection between the hitch valve and the hydraulic cylinders.

   1. Repair the leak, if necessary.

2. Determine if the problem is an electrical problem.

   1. Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Adjustment". Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Troubleshooting".

3. Check the piston seals in the hydraulic cylinders for excessive wear.

   1. Repair the piston seals, if necessary.

4. Check the solenoid valve for excessive wear.

   1. Repair the solenoid valve, if necessary.

5. Check the spool in the hitch valve for excessive wear.

   1. Repair the spool, if necessary.

6. Check for foreign material in the solenoid valve. Check for foreign material in the hitch valve.

   1. Repair the valves, if necessary.

7. Make sure that the hitch relief valve is not worn. Also, make sure that the hitch relief valve is not loose.

   1. If necessary, repair the hitch relief valve or tighten the hitch relief valve.

The hitch moves too fast.

1. Check the electrical components of the hitch control system for correct adjustment and operation.

   1. Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Adjustment". Refer to Systems Operation/Testing and Adjusting, "Hitch Control System Troubleshooting".

The oil from the hydraulic system is being transferred into the transmission.

1. Disconnect the signal line that runs from the transmission to the diverter valve. Check for leakage at the port on the diverter valve. The engine should be running and the transmission should be in NEUTRAL.

   1. Very little oil should be leaking at the port. If more than 0.01 L (0.012 qt) leaks in 20 minutes, replace the diverter valve.

2. Check for the buildup of debris at the return oil screen.

   1. Remove any debris from the screen. Debris buildup at the screen can distort the implement pump shaft seal.

3. Inspect the steering filter base for correct orientation.

   1. If the orientation of the steering filter base needs adjusted, the filter must be changed.

4. Check the implement pump shaft seal.

   1. Replace the shaft seal.

5. Check the shaft seal for the steering pump .

   1. Replace the shaft seal.

Troubleshooting for the Steering Hydraulic System

Problem List

• "The temperature of the hydraulic oil in the tank is high."

• "The charge oil pressure for the steering hydraulic system is not correct."

• "The pilot oil pressure from the steering control valve is not correct."

• "The steering pump oil pressure is not correct."

• "The machine turns slowly in both directions."

• "The machine turns slowly in one direction."

• "The machine turns in the opposite direction of the steering wheel in forward and/or reverse."

• "The turns of the machine are jerky or the turns are unstable."

• "The machine turns correctly during roading, but the machine turns slowly in one direction when the machine is loaded."

• "The engine lugs more than normal when you steer the machine."

• "The engine speed surges when you steer the machine."

• "The machine drifts in one direction in first gear when the engine is at low idle."

• "The steering wheel rotation is excessive before the turn begins."

• "The guide blocks on the belts show abnormal wear after the initial 400 hour break-in period."

Probable Causes

The temperature of the hydraulic oil in the tank is high.

1. Check the techniques of the operator. The load on the system may be too high.

   1. Change the operating techniques in order to reduce the load on the system.

2. Check the hydraulic oil tank level. The level may be too low.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

   2. Check for oil aeration by taking an oil sample. If aeration is found, see "There is a large amount of air in the oil".

3. The outside air temperature may be too hot.

   1. Change the operating techniques in order to reduce the load on the system.

4. Check the actual temperature of the oil.

   1. Insert a thermometer into the oil filler tube.

   2. If the temperature is below 82 °C (180 °F), there is an electrical problem with the temperature sensing system. Refer to Troubleshooting, RENR1803, "Electronic System".

5. Verify that the pump proceeds to low pressure standby when the implements and the hitch are not being operated.

   1. Perform the low pressure standby test. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".
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   Illustration 16	g00566981
   Earlier compensator valve (1) Flow compensator spool

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   Illustration 17	g00637437
   Later compensator valve (1) Flow compensator spool

   2. If the pump does not proceed to low pressure standby, make sure that flow compensator spool (1) moves freely inside the compensator valve.

   3. If necessary, repair the failure.

6. Make sure that the correct viscosity of oil is in the system.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

7. Verify that the pressure compensator spool valve opens at the correct oil pressure.

   1. Perform the high pressure stall test for the implement pump. Refer to Systems Operation/Testing and Adjusting, "Implement Pump Discharge Pressure Tests".

8. Check for pump wear.

   1. Perform the pump efficiency check for the implement hydraulic pump. Refer to Systems Operation/Testing and Adjusting, "Pump Efficiency Check".

9. Check for a restriction in an oil passage.

   1. Determine the cause. If necessary, repair the machine.

10. Determine if the oil cooler bypass valve is stuck open.

    1. Determine the cause. If necessary, repair the oil cooler bypass valve.

11. Check for a blockage in the oil cooler.

    1. Determine the cause. If necessary, repair the machine.

12. Make sure that the multifunction valves are adjusted correctly.

    1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

13. Make sure that the charge relief valve is adjusted correctly.

    1. Perform the pressure test for the charge oil of the steering system. Refer to Systems Operation/Testing and Adjusting, "Steering System Charge Oil Pressure Test".

14. Check the steering pump for excessive wear.

The charge oil pressure for the steering hydraulic system is not correct.

1. Check the hydraulic oil level in the tank.

   1. Check the hydraulic oil level in order to determine if there is enough oil in the tank.

   2. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Make sure that the correct viscosity of oil is in the system.

   1. Refer to Operation and Maintenance Manual, SEBU7072.

3. The charge relief valve is not adjusted correctly.

   1. Perform the pressure test for the charge oil of the steering system. Refer to Systems Operation/Testing and Adjusting, "Steering System Charge Oil Pressure Test".

4. The high pressure cutoff of the multifunction valves is not adjusted.

   1. Test the high pressure cutoff of the steering system. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

5. Check the charge pump for excessive wear.

   1. Perform the pump efficiency test.

The pilot oil pressure from the steering control valve is not correct.

1. Make sure that the charge oil pressure is not too low.

   1. Test the charge oil pressure for the steering system. Refer to Systems Operation/Testing and Adjusting, "Steering System Charge Oil Pressure Test".

   2. If the charge oil pressure is too low, refer to "The charge oil pressure for the steering hydraulic system is not correct".

2. Check the operation of the pressure regulating valve.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Control Pressure Regulating Test".

   2. If the pressure regulating valve is not operating correctly, go to Step 3.

   3. If the pressure regulating valve is operating correctly, go to Step 4.

3. Check the regulating spring in the pressure reducing valve in the steering control in order to make sure that the spring is not broken.

   1. Remove the regulating spring from the pressure reducing valve in order to inspect the spring.

   2. Replace the spring, if necessary.

4. Check the steering control for correct operation.

   1. Make sure that the steering wheel rotates freely.

   2. If the steering wheel does not rotate freely, remove the steering control from the steering column. Then, check the steering control.

5. Check the diverter valve for damage. Check the diverter valve for leakage.

   1. Repair the diverter valve, if necessary.

The steering pump oil pressure is not correct.

1. Make sure that the multifunction valves are adjusted correctly.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

2. Make sure that the pilot oil pressure from the steering control valve is correct.

   1. Test the pilot oil pressure from the steering control valve. Refer to Systems Operation/Testing and Adjusting, "Steering Control Pilot Oil Pressure Test".

   2. If the pilot oil pressure is not correct, refer to "The pilot oil pressure from the steering control valve is not correct".

3. Make sure that the hydraulic displacement control valve is operating correctly.

   1. Check the operation of the hydraulic displacement control valve. Refer to Systems Operation/Testing and Adjusting, "Hydraulic Displacement Control Valve Test".

   2. Check the upstroke of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump Upstroke/DeadbandTest".

4. Make sure that the charge pump is operating correctly.

   1. Check the charge oil pressure. Refer to Systems Operation/Testing and Adjusting, "Steering System Charge Oil Pressure Test".

   2. If the charge oil pressure is not correct, refer to "The charge oil pressure for the steering hydraulic system is not correct".

5. Check the pump for excessive wear.

   1. Perform the pump efficiency check.

The machine turns slowly in both directions.

1. Check for leaks in the circuit between the steering pump and the steering motor.

   1. Repair any leaks, if necessary.

2. Check the steering pump oil pressure.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

   2. If the steering pump oil pressure is not correct, refer to "The steering pump oil pressure is not correct".

3. Check the steering motor for excessive wear.

   1. Test the case drain pressure of the steering motor.

The machine turns slowly in one direction.

1. Check for leaks in the circuit between the steering pump and the steering motor.

   1. Repair any leaks, if necessary.

2. Make sure that the pilot oil pressure from the steering control valve is correct.

   1. Test the pilot oil pressure from the steering control valve.

   2. If the pilot oil pressure is not correct, refer to "The pilot oil pressure from the steering control valve is not correct".

3. Make sure that the hydraulic displacement control valve is operating correctly.

   1. Check the operation of the hydraulic displacement control valve. Refer to Systems Operation/Testing and Adjusting, "Hydraulic Displacement Control Valve Test".

   2. Check the upstroke of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump Upstroke/DeadbandTest".

4. Check the tension of the belts.

   1. Refer to Systems Operation/Testing and Adjusting, SENR1734, "Track - Tension or Detension".

5. Make sure that the multifunction valves are adjusted correctly.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

The machine turns in the opposite direction of the steering wheel in forward and/or reverse.

1. Make sure that the diverter valve is getting pilot oil from the No. 8 clutch in the transmission control when the machine is operated in reverse.

   1. Repair the diverter valve, if necessary.

2. The oil lines that connect the steering control valve to the diverter valve are crossed.

   1. Switch the lines and test the steering.

3. The oil lines that connect the diverter valve to the steering pump are crossed.

   1. Switch the lines and test the steering.

4. Make sure that the diverter valve is operating correctly.

   1. Make sure that the spool moves freely.

   2. Make sure that the return spring is not broken.

   3. Repair the diverter valve, if necessary.

The turns of the machine are jerky or the turns are unstable.

1. Check for a large amount of air in the oil.

   1. Take a sample of oil from the sump.

   2. If there is a large amount of air in the oil, refer to "There is a large amount of air in the oil".

2. Make sure that the multifunction valves are adjusted correctly.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

3. Make sure that the pressure regulating valve on the steering control valve operates correctly.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Control Pressure Regulating Test".

   2. If the pressure regulating valve is not operating correctly, check the spool and check the springs.

4. Make sure that the hydraulic displacement control valve is operating correctly.

   1. Check the operation of the hydraulic displacement control valve. Refer to Systems Operation/Testing and Adjusting, "Hydraulic Displacement Control Valve Test".

   2. Check the upstroke of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump Upstroke/DeadbandTest".

5. Check for debris in the oil.

   1. If there is debris in the oil, find the cause of the debris.

The machine turns correctly during roading, but the machine turns slowly in one direction when the machine is loaded.

1. Make sure that the multifunction valves are adjusted correctly.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

2. Check the tension of the belts.

   1. Refer to Systems Operation/Testing and Adjusting, SENR1734, "Track - Tension or Detension".

The engine lugs more than normal when you steer the machine.

1. Make sure that the multifunction valves are adjusted correctly.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

2. Check the techniques of the operator. The load on the system may be too high.

   1. Change the operating techniques in order to reduce the load on the system.

The engine speed surges when you steer the machine.

1. Make sure that the multifunction valves are adjusted correctly.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

2. Make sure that the pilot oil pressure from the steering control is correct.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Control Pilot Oil Pressure Test".

   2. If the pilot oil pressure is not correct, refer to "The pilot oil pressure from the steering control valve is not correct".

The machine drifts in one direction in first gear when the engine is at low idle.

Note: The maximum allowable drift with no operator input is 1.8 m (6 ft) over a distance of 61 m (200 ft).

1. Check the tension of the belts.

   1. Refer to Systems Operation/Testing and Adjusting, SENR1734, "Track - Tension or Detension".

2. Check the deadband of the steering system.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Pump Upstroke/Deadband Test".

3. Make sure that the pilot oil pressure from the steering control is correct.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Control Pilot Oil Pressure Test".

   2. If the pilot oil pressure is not correct, refer to "The pilot oil pressure from the steering control valve is not correct".

4. Check the operation of the steering control.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Control Bench Test".

The steering wheel rotation is excessive before the turn begins.

1. Check the steering pump oil pressure.

   1. Test the high pressure cutoff of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump High Pressure Cutoff Pressure Test".

   2. If the steering pump oil pressure is not correct, refer to "The steering pump oil pressure is not correct".

2. Make sure that the hydraulic displacement control valve is operating correctly.

   1. Check the operation of the hydraulic displacement control valve. Refer to Systems Operation/Testing and Adjusting, "Hydraulic Displacement Control Valve Test".

   2. Check the upstroke of the steering pump. Refer to Systems Operation/Testing and Adjusting, "Steering Pump Upstroke/DeadbandTest".

3. Check the steering motor for excessive wear.

   1. Test the case drain pressure for the steering motor.

4. Make sure that the steering control is operating correctly.

   1. Refer to Systems Operation/Testing and Adjusting, "Steering Control Bench Test".

The guide blocks on the belts show abnormal wear after the initial 400 hour break-in period.

1. Check for the correct alignment of the belts.

   1. Refer to Systems Operation/Testing and Adjusting, SENR1734, "Track Alignment".

Troubleshooting for the Brake System

Problem List

• "When the brakes are applied, the brakes react slowly."

• "The service brakes do not release."

• "The braking is insufficient."

• "The brakes will not release completely."

• "The service brakes do not operate."

• "The application of the service brake is not smooth."

• "The accumulator charging cycle repeats frequently when brakes are not being used."

• "The accumulator starts to charge, but the accumulator does not reach the high limit."

• "The accumulator charges frequently while the brakes are being held."

• "The accumulator charging time is too long."

• "The accumulator fails to start charging."

• "The charging valve cycles very rapidly."

Probable Causes

When the brakes are applied, the brakes react slowly.

1. Check the hydraulic oil tank level. The level may be too low. Check for oil aeration. If necessary, purge the brake lines of air.
   • Refer to Systems Operation/Testing and Adjusting, SENR1741 for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Check the hydraulic lines and fittings for any leaks.

   1. Repair the hydraulic lines, if necessary.

3. Check the brake lines for dents. A restriction may cause a decrease in oil flow.

   1. Replace the damaged brake line, if necessary.

4. Check dry nitrogen charge in the accumulator.

   1. See Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Service Brake System Accumulator".

5. Check the service brake pedal linkage for proper adjustment.

   1. Refer to Specifications, SENR1740, "Implement, Steering and Brake Hydraulic Systems" for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

6. Check the brakes for damage.

   1. Inspect the brakes and repair the brakes, as required.

The service brakes do not release.

1. Check the service brake pedal linkage for proper adjustment.

   1. Refer to Specifications, SENR1740, "Implement, Steering and Brake Hydraulic Systems" for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

2. Check brakes for damage.

   1. Inspect the brakes and repair the brakes, as required.

3. Check the operation of the brake valve.

   1. Inspect the ball valve within the brake valve.

   2. Inspect the pistons within the brake valve for binding.

   3. Replace the brake valve.

The braking is insufficient.

1. Check the hydraulic oil tank level. The level may be too low. Check for oil aeration. If necessary, purge the brake lines of air.
   • Refer to Systems Operation/Testing and Adjusting, SENR1741 for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Check the hydraulic lines and fittings for leaks.

   1. Inspect the components and repair the components, as required.

3. Check the service brake pedal linkage for proper adjustment.

   1. Refer to Specifications, SENR1740, "Implement, Steering and Brake Hydraulic Systems" for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

4. Check the brake line for dents which may restrict the oil flow.

   1. Replace any damaged brake lines.

5. Check the dry nitrogen charge in the accumulator.

   1. See Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Service Brake System Accumulator".

6. Check the operation of the brake valve.

   1. Cap the line from the brake valve. Actuate the brakes. If pressure builds up in the line that is capped, the problem is in the brakes.

   2. Inspect the brake valve for a broken pressure regulating spring.

   3. Inspect the brake valve for a cut boot which allows dirt to accumulate under the piston flange.

   4. Replace the brake valve.

7. Check the brakes for damage.

   1. Inspect the brakes and repair the brakes, as required.

8. Check the brake pads for oil or grease.

   1. Inspect the brake pads and repair the brake pads, as required.

The brakes will not release completely.

1. Check the service brake pedal linkage for proper adjustment.

   1. Refer to Specifications, SENR1740, "Implement, Steering and Brake Hydraulic Systems" for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

2. Check the drain passage to the brake valve for excessive back pressure.

   1. Inspect the drain passage for a restriction. Remove the restriction.

3. Check the operation of the brake valve.

   1. Inspect the brake valve for stuck pistons. Repair the brake valve, as required.

   2. Replace the brake valve.

4. Check the brakes for damage.

   1. Inspect the brakes and repair the brakes, as required.

The service brakes do not operate.

1. Check the hydraulic oil tank level. The level may be too low. Check for oil aeration.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Check the service brake pedal linkage for proper adjustment.

   1. Refer to Specifications, SENR1740, "Implement, Steering and Brake Hydraulic Systems" for Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors.

3. Check for a broken brake line or a damaged brake line.

   1. Replace any broken brake lines or damaged brake lines.

4. Check for adequate pressure from the implement pump.

   1. Check for a malfunctioning system relief valve which may cause inadequate pressure in the system.

   2. Perform the "Pump Effeciency Check" that is in Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Implement Hydraulic Pump".

5. Check the operation of the brake valve.

   1. Cap the line from the brake valve. Actuate the brakes. If the pressure builds up in the line that is capped, the problem is in the brakes.

   2. Inspect the brake valve for stuck pistons. Repair the brake valve, as required.

   3. Inspect the brake valve for a broken pressure regulating spring.

   4. Inspect the brake valve for a cut boot which allows dirt to accumulate under the piston flange.

   5. Replace the brake valve.

6. Check the brakes for damage.

   1. Inspect the brakes and repair the brakes, as required.

The application of the service brake is not smooth.

1. Install a pressure gauge at the brakes.

   1. Check for fluctuations in the pressure as the brakes are applied.

2. Check the operation of the brake valve.

   1. Inspect the brake valve for excessive shims in the brake valve. Repair the brake valve, as required.

   2. Replace the brake valve.

3. Check the brakes for damage.

   1. Inspect the brakes and repair the brakes, as required.

The accumulator charging cycle repeats frequently when brakes are not being used.

1. Check the accumulator lines and the accumulator fittings for leaks.

   1. Repair the accumulator, as required.

2. Check the dry nitrogen charge in the accumulator.

   1. See Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Service Brake System Accumulator".

3. Check the line to the accumulator for a restriction.

   1. Replace the line.

4. Check the operation of the brake valve.

   1. Inspect the brake valve for leaking seals, a leaking poppet, or a leaking pilot valve ball.

   2. Make sure that the ball valve is seating.

   3. Replace the brake valve.

The accumulator starts to charge, but the accumulator does not reach the high limit.

1. Check the hydraulic oil tank level. The level may be too low. Check for oil aeration.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Check for adequate pressure from the implement pump.

   1. Check for a malfunctioning system relief valve which may cause inadequate pressure in the system.

   2. Perform the "Pump Effeciency Check" that is in Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Implement Hydraulic Pump".

3. Check the operation of the brake valve.

   1. Inspect the pilot valve body for damaged O-rings.

   2. Inspect the charging valve spool for damaged O-rings.

   3. Replace the brake valve.

The accumulator charges frequently while the brakes are being held.

1. Check the brake line and fittings for leaks.

   1. Repair the components, as required.

2. Check the dry nitrogen charge in the accumulator.

   1. See Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Service Brake System Accumulator".

3. Check the operation of the brake valve.

   1. Inspect the brake valve for leaking seals.

   2. Replace the brake valve.

The accumulator charging time is too long.

1. Check the hydraulic oil tank level. The level may be too low. Check for oil aeration.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Check for adequate pressure from the implement pump.

   1. Check for a malfunctioning system relief valve which may cause inadequate pressure in the system.

   2. Perform the "Pump Effeciency Check" that is in Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Implement Hydraulic Pump".

3. Check the operation of the brake valve.

   1. Inspect the brake valve for a charging valve spring that is broken or damaged.

   2. Check for dirt in the filter within the brake valve.

   3. Check the poppet for being stuck or partially closed.

   4. Replace the brake valve.

The accumulator fails to start charging.

1. Check the hydraulic oil tank level. The level may be too low. Check for oil aeration.

   1. Check the hydraulic oil tank level on the sight gauge in order to determine if there is enough oil in the hydraulic tank. The oil level should be between the "ADD" and "FULL" marks on the sight gauge.

2. Check for adequate pressure from the implement pump.

   1. Check for a malfunctioning system relief valve which may cause inadequate pressure in the system.

   2. Perform the "Pump Effeciency Check" that is in Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Implement Hydraulic Pump".

3. Check the operation of the brake valve.

   1. Inspect the brake valve for a broken pilot valve spring.

   2. Inspect the brake valve for a broken charging valve spring.

   3. Inspect the brake valve for a damaged O-ring on the charge spool.

   4. Inspect the brake valve for a stuck charge spool.

   5. Check for dirt in the filter within the brake valve.

The charging valve cycles very rapidly.

1. Check the dry nitrogen charge in the accumulator.

   1. See Systems Operation/Testing and Adjusting, SENR1741, "Implement, Steering and Brake Hydraulic Systems-Service Brake System Accumulator".

2. Check the operation of the brake valve.

   1. Inspect the brake valve for a worn pilot valve.

   2. Replace the brake valve.