VALVE GP-CHECK 2014791 - Caterpillar

To prevent personal injury when checks are made while the machine is in operation, make sure only approved personnel are on the machine. Keep other personnel off the machine and in view of the operator. Make sure checks are done in an open area.
Steering Turn Diameter Check
Move the machine to a flat, dry open area. When turning the machine, check that there is a limited amount of track slip. Make sure that the steering linkage is adjusted.
Start and run the engine at HIGH IDLE. Raise all the implements to the FULL RAISE position and return the levers to the HOLD position.
Release the parking brake and put the transmission in FIRST SPEED FORWARD.
Place the steering control handle in the full steer left position. Keep all implement controls in the HOLD position.
Make a full 360 degree turn.
Stop the machine after the full turn. Lower all implements to the ground and stop the engine.
Measure distance (A) as shown. Distance (A) should be 1.2 to 1.8 m (3.9 to 5.9 ft).
Repeat steps 1 through 7 with the steering control handle in the FULL STEER RIGHT position.
If the distances measured in Steps 7 and 8 are within specification, the steering hydraulic system is operating correctly. If the distances measured in Steps 7 and 8 are not within specification, proceed to Step 10.
Do Steps 1 through 6 again with steering control handle at the FULL STEER RIGHT and the FULL STEER LEFT positions with the bulldozer control lever held in the FULL RAISE position.
Measure distance (A) as shown. Distance (A) should be 1.2 to 1.8 m (3.9 to 5.9 ft).
Refer to the following in order to help diagnose the steering system.
Illustration 1 g00491216
Full Turn Diameter (A) Diameter of the turnProblem: The machine will not turn. The steering radius is gradual.Possible Causes:
The steering linkage is disconnected or broken.
The pump is not connected to the pump drive or the pump drive shaft is broken.
The oil level in the hydraulic tank is low.
The steering pump or the motor has failed.
There is no charge or pilot pressure.
The parking brake is ON. The problem is caused by the following causes:
The linkage is misadjusted.
The power train oil pressure is low.
Internal leakage in brake valve
There is a mechanical problem in the drive train.Problem: Distance (A) is too large in Steps 7 and 8, but within specification in Steps 10 and 11.Possible Causes:
The implement pressure reducing valve is not shifting at the correct pressure.
The implement pump standby pressure is too low.Problem: Distance (A) is too large in Steps 7, 8, 10 and 11.Possible Causes:
The charge pressure is low. The problem is caused by the following causes:
The charge pump is defective or worn.
The cold oil bypass valve is defective.
The charge pressure relief valve is set too low.
There is high leakage at the motor flushing valve.
The steering pump or the steering motor has failed.
There is low pilot pressure. The problem is caused by the following causes:
The tiller is improperly adjusted.
Improperly set pilot valves.
There is excessive leakage in the pilot valve.
There is a blocked supply line