TH220B, TH330B, TH340B, TH350B, TH355B, TH360B, TH460B, TH560B and TH580B Telehandlers Caterpillar

Troubleshooting The Steering System

Show/hide table

Personal injury or death can result from sudden machine movement. Sudden movement of the machine or release of oil pressure can cause injury to persons on or near the machine. To help prevent possible injury or death, refer to the information in Testing and Adjusting, "Machine Preparation for Troubleshooting".

Problem List

• The hydraulic pump is noisy.

• The steering is jerky and the steering cylinder rod does not move smoothly.

• The steering wheel is difficult to turn.

• Machine steers slowly.

• The steering fails to auto-align when you change from one steering mode to another steering mode.

• The steering fails to change from one steering mode to another steering mode without the auto-align feature.

• There is a loss of steering.

• Steering wheel turns but wheels do not move.

Probable Causes

The Hydraulic Pump Is Noisy

• Low oil level

• The pump is worn.

• A loose connection on the suction side of the pump is allowing air to be drawn in to the system.

• Wrong oil viscosity

• Contamination within the priority spool

• Aeration within hydraulic oil

Steering Is Jerky And The Steering Cylinder Rod Does Not Move Smoothly

• Low oil level

• The pump is worn.

• A loose connection on the suction side of the pump is allowing air to be drawn in to the system.

• Wrong oil viscosity

• Contamination within the priority spool

• Air in the hydraulic oil

The Steering Wheel Is Difficult To Turn

• Low oil level

• Bearings in the steering column are not within the specification.

• The joints on the steering column are damaged or the joints are binding.

• Damage to the spool or to the sleeve in the metering section of the steering metering pump

• A sticking spool for the metering pump is caused by either dirt in the system or distortion of the spool.

• Steering cylinder is damaged.

• Oil is excessively cold.

• Insufficient flow of oil from the pump

• Hydraulic lines are plugged or damaged.

• The hydraulic pump is not within the specification.

Machine Steers Slowly

• Oil in the hydraulic system is not at operating temperature.

• The steering system hydraulic lines leak.

• The cylinder has an oil leak.

• There is insufficient flow of oil from the pump.

• The hydraulic lines are plugged or damaged.

• The hydraulic pump is not within the specification.

• The oil is the wrong oil viscosity.

• Oil aeration.

The Steering Fails To Auto-Align When You Change From One Steering Mode To Another Steering Mode

• The circuit for the all wheel steer has blown a fuse.

• The auto-align function is turned off.

• The steering mode switch is faulty.

• A sensor for the rear or front alignment is faulty.

• The adjustment is not in alignment with the sensor when rear wheels are straight.

• A relay for the crab steer or circle steer for the steering alignment is faulty.

• Steering is too fast.

• Steering line or hose to the rear of the axle is damaged or plugged.

• The spool is sticking in the steering selector valve.

The Steering Fails To Change From One Steering Mode To Another Steering Mode Without The Auto-Align Feature

• The circuit for the all wheel steer has blown a fuse.

• The rear axle is not aligned.

• The steering mode switch is faulty.

• A relay for the crab steer or circle steer for the steering alignment is faulty.

• Steering line or hose to the rear of the axle is damaged or plugged.

• The spool is sticking in the steering selector valve.

There Is A Loss Of Steering

• Oil level in the hydraulic tank is too low.

• The steering hose or the steering line is damaged.

• The joints on the steering column are damaged.

• The check valve in the steering metering pump may be stuck open.

• The priority valve in the inlet manifold is stuck.

• The steering relief valve is sticking open.

• Steering cylinder seized.

• The pump is damaged.

• The priority spool seized or the priority spool is blocked.

Steering Wheel Turns But Wheels Do Not Move

• Oil level in the hydraulic tank is too low.

• The steering hose or the steering line is damaged.

• The joints on the steering column are damaged.

• There is dirt in the steering metering pump.

• The centering springs for the steering metering pump are broken. You are able to steer even if the centering springs are broken. The steering control will be diminished.

• The steering metering pump is not timed correctly.

• The pin, the rotor, and the drive shaft are not aligned.