BRACKET AS 5403981 - Caterpillar

Charge Pump Pressure Becomes Low
When the engine is running, the makeup valves open and both sides of the drive loop fill with oil at charge pressure.The charge pump is a pressure compensated piston pump. This pump provides charge oil for the steering hydraulic circuit. This pump also provides pilot supply oil for the implement valves.Test and adjust the Charge Pressure. Refer to Specifications, Systems Operations, and Testing and Adjusting, UENR4065, "Piston Pump (Steering Charge and Pilot Pressure) - Test and Adjust".Crossover Relief and Makeup Valves
Test and adjust the crossover relief and makeup valves. Refer to Specifications, Systems Operations, and Testing and Adjusting, UENR4065, "Piston Pump (Steering) - Test and Adjust".Oil from the high-pressure side of the steering loop may leak across to the low-pressure side of the loop under one of the following conditions:
The relief function or the makeup function of one of the valves is stuck open
One of the valves springs is weak
One of the valves springs is broken
One of the valves springs is misadjustedIf one of the conditions listed above exists, the necessary high pressure may not be possible or may not be maintained in one or both sides of the steering loop.Test the neutral position for the steering pump control valve. Refer to Specifications, Systems Operations, and Testing and Adjusting, UENR4065, "Piston Pump (Steering) - Test and Adjust". If the neutral position of the steering pump control valve is incorrect (off-center while in the NO STEER condition), the steering pump control valve will command the actuator piston to move off-center when there is no steering request. This condition may cause the machine to stray from straight-line travel in a NO STEER condition, and may cause the machine to steer more sharply in one direction than the other.Charge Pump Flow Becomes Low
If the charge pump becomes too inefficient and cannot produce the required oil flow, steering will be slow to react, turns will not be as sharp, or the machine may not steer at all.Use a flow meter in order to test the