PUMP GP-GEAR 2118744 - Caterpillar

Probable Causes for Problems in the Implement Pump and System
The response of one implement is too slow.
The implement valve spool does not fully shift.
A pilot line has blockage.
The wrong control valve for the implement is installed in the valve stack.
The control valve is suspect.All implement cycle times are too slow.
The purge valve for air on the implement pump is open.
The margin pressure setting is too low.
The pilot system has a blockage or a leakage. The problem is caused by the following causes:
The pilot line is blocked or the pilot line is not hooked up.
The shuttle valve is stuck open or the valve has a failed seal.
The flow control sleeve that is behind the flow control spring has a failed seal.
The plug in the end of the control valve spool has a failed seal.
The pump control is suspect.
The pump is not operating at full stroke.
The diameter of the hoses or the fittings are incorrect.The implement droops when the control lever is moved from HOLD to LIFT.
The load check valve is not closing. The problem is caused by the following causes:
The spring in the load check valve is weak or broken.
The load check valve has dirt or debris.
The valve seat in the load check valve is suspect.The implement drift is excessive.
The valve spool in the control valve is not correctly centered. The problem is caused by the following causes:
The spring on the valve spool is broken.
The valve spool is sticking.
A blockage exists in one of the pilot lines to the control valve.
The cylinder piston seals are leaking excessively.
The makeup valve has excessive leakage or the makeup valve seals have failed.
The quick-drop valve or the end stroke bypass valves are leaking excessively.
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