Note: Refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" before you start the troubleshooting.
Troubleshooting will help to accomplish the following items:
- Determine the cause of poor performance of the systems.
- Locate the source of any hydraulic oil leaks.
Start the engine. Operate the engine at high idle until the hydraulic oil reaches normal operating temperature. Troubleshooting should be done when the hydraulic oil is at the normal operating temperature.
Problem
The temperature of the hydraulic oil is excessively high.
Probable Cause
- The viscosity of the hydraulic oil is incorrect.
- The pressure compensator valve activates at a hydraulic oil pressure that is lower than the specified pressure setting.
- The cushion-hitch piston pump is excessively worn.
- A restriction exists in a hydraulic oil passage.
- The load on the cushion-hitch is excessively high.
- The pressure setting for the main relief valve is too low.
- The vane pump for the implements is excessively worn.
- Air bubbles are present in the hydraulic oil.
- The outside air temperature is excessively hot and the outside air temperature prevents proper cooling of the hydraulic oil.
Problem
The vane pump for the implements makes unusual noise. The implement cylinder rods do not move smoothly.
Probable Cause
- The viscosity of the hydraulic oil is incorrect.
- The main relief valve opens at low oil pressure.
- The supply line to the vane pump for the implements has a loose connection.
- The vane pump for the implements is excessively worn.
Problem
The cushion-hitch piston pump makes an excessive amount of noise. The rod of the load cylinder does not move smoothly.
Probable Cause
- The viscosity of the hydraulic oil is incorrect.
- The pressure compensator valve activates at a hydraulic oil pressure that is lower than the specified pressure setting.
- The supply line to the cushion-hitch piston pump has a loose connection.
- The cushion-hitch piston pump is excessively worn.
- The cushion-hitch piston pump is receiving an inadequate amount of inlet oil from the supply line to the cushion-hitch piston pump.
Problem
Air bubbles are present in the hydraulic oil.
Probable Cause
- There is a leak or a loose connection in the oil line between the hydraulic tank and the vane pump for the implements.
- There is a leak or a loose connection in the oil line between the hydraulic tank and the cushion-hitch piston pump.
- There was a failure to correctly purge the hydraulic system after assembly, inspection or testing was completed.
- There is leakage around the cylinder seals.
Problem
The output of the vane pump for the implements is too low.
Probable Cause
- The vane pump for the implements is excessively worn.
- The hydraulic oil level in the hydraulic oil tank is low.
- The viscosity of the hydraulic oil is incorrect.
Problem
The output of the cushion-hitch piston pump is excessively low.
Probable Cause
- The hydraulic oil level in the hydraulic oil tank is low.
- The viscosity of the hydraulic oil is incorrect.
- The cushion-hitch piston pump is excessively worn.
Problem
The hydraulic oil pressure for the cushion-hitch or the bail is low.
Probable Cause
- The pressure compensator valve activates at a hydraulic oil pressure that is lower than the specified pressure setting.
- The cushion-hitch piston pump is excessively worn.
- The hydraulic system has a failed O-ring seal.
- A failure in the leveling valve is allowing hydraulic oil to flow to the drain.
Problem
The rod of the load cylinder does not fully extend.
Probable Cause
- The pressure compensator valve activates at a hydraulic oil pressure that is lower than the specified pressure setting.
- The cushion-hitch piston pump is excessively worn.
- The hydraulic system has a failed O-ring seal.
- The linkage for the leveling stem of the leveling valve requires an adjustment.
Problem
When the engine is stopped, the leveling valve does not automatically turn off the cushion ride.
Probable Cause
- The directional spool in the leveling valve does not move upward.
- Debris is plugging an orifice in the leveling valve.
Problem
The response of one implement is too slow.
Probable Cause
- The lever linkage is restricted or the travel is restricted.
- The valve stem that is installed in the main control valve is incorrect for the implement.
- The main control valve has failed.
- The main relief valve is set too low.
Problem
The response of all the implements are too slow.
Probable Cause
- There is contamination in the main control valve.
- There is air in the system.
- The main relief valve is set too low or the main relief valve leaks.
Problem
The performance of a single implement circuit is erratic.
Probable Cause
- The main control valve is contaminated.
- The valve stem is incorrect for this circuit.
Problem
The performance of all the implement circuits are erratic.
Probable Cause
- The hydraulic oil in the hydraulic system has not reached normal operating temperature.
- The vane pump for the implements has failed.
- There is air in the hydraulic system.
Problem
Any implement moves with the control lever in the HOLD position.
Probable Cause
- The cylinder piston seals have failed or the cylinder piston seals are worn.
- The valve stem seals have failed or the valve stem seals are worn.
- The carry-check valve for the bowl has failed.
- The line relief valve for the bail is malfunctioning.
Problem
When the implement is first activated, the implement surges.
Probable Cause
- The slots in the valve stem are incorrectly machined.
- There is air in the circuit.
Problem
Too much effort is needed to move the control lever.
Probable Cause
- The lever linkage is restricted or the lever linkage has interference.
- The bias spring in the main control valve is missing or the bias spring in the main control valve is incorrect.
- The main control valve has a sticking control stem or the main control valve has a failed control stem.
Problem
The response of the implements is too fast.
Probable Cause
- An incorrect valve stem is installed in the main control valve.
- The main control valve has failed.
Problem
The bail has slow movement.
Probable Cause
- The cushion-hitch pump has low output.
- There is a seal failure on the bail cylinder or the piston.
Problem
The bail lowers too fast or the bail does not lower smoothly.
Probable Cause
- There is a loose hose connection on the inlet side of the cushion-hitch pump.
- There is air in the push-pull hydraulic system.
Problem
Hydraulic oil pressure to the bail cylinder is low.
Probable Cause
- The pressure compensator valve activates at a hydraulic oil pressure that is lower than the specified pressure setting.
- The cushion-hitch pump is excessively worn.
- The hydraulic system has a failed seal.
- The piston behind the spring for the pressure relief valve in the push-pull control valve is not free to move when the solenoid valve is in the BAIL RAISE position.
Problem
Hydraulic oil pressure to the bail cylinder is high.
Probable Cause
- The pressure setting of the pressure control valve is not correct.
- The piston behind the spring in the pressure relief valve in the push-pull control valve is not free when the bail is fully raised or when the bail control switch is in the BAIL DOWN position.