PUMP GP-PISTON 4328564 - Caterpillar

In Chassis Test and Adjust Procedure
Table 1
Required Tools    
Part Number    Description    Required Amount    
198-4240     Digital Pressure Indicator     1    
2J-5608     Cover     1    
4J-0527     O-Ring Seal     1    Note: Make sure that the filters and the screens are clean before you test any pressures. Make sure that the oil is at operating temperature before you perform this test.
Illustration 1 g01273372
(1) Pressure tap on the pump
Illustration 2 g01273373
(2) Tube assembly (3) Brake oil cooler relief valve
Illustration 3 g00532762
Section view of brake oil cooler relief valve (3) (3) Brake oil cooler relief valve (4) Shims
Connect 198-4240 Digital Pressure Indicator to pressure tap (1) .
Start the engine. Run the engine at low idle.
Raise the dump body.
Move the control lever for the hoist control to the Float.
Illustration 4 g01566077
Typical
When the display indicates the dump body has entered SNUB, look at the pressure gauge. The pressure reading should be less than 1725 kPa (250 psi).Note: The Snub position can be read on the ET screen, the Messenger screen, or the Advisor screen.Note: The pressure reading was the result of bench testing the relief valve at a flow rate of 38 L/min (10 US gpm). The flow rate of the pump at low idle is 167 L/min (44 US gpm). The resulting pressure may be higher than the value that is provided.
The pressure can be lowered in ET by using the "hoist Lower adjustment". See Special Instruction, REHS5053, "777G Off-Highway Truck Assembly", "Adjustment for Hoist Lower Value".Note: Special Instruction, REHS5053, "777G Off-Highway Truck Assembly", "Adjustment for Hoist Lower Value" is not complete yet.
Stop the engine.
Remove the test equipment.Bench Test and Adjustment
Table 2
Shims For Adjusting The Relief Valve Pressure Setting    
Part Number     Thickness     Pressure Change    
8B-4624    
0.81 mm (0.032 inch)    
30 kPa (4 psi)    Problem: The pressure is less than 586 14 kPa (85 2 psi).
Probable Cause
Brake oil cooler relief valve (3) is stuck open.
Brake oil cooler relief valve (3) is set too low. Add shims (4). Refer to Table 2.Problem: The pressure is greater than 586 14 kPa (85 2 psi).
Probable Cause
Brake oil cooler relief valve (3) is set too high. Remove shims (4). Refer to Table 2.