PUMP GP-PS&GR 0R4221 - Caterpillar

Illustration 1 g01429098
Pump compartment
(1) Pressure tap (delivery pressure for drive pump)
(2) Pressure tap (delivery pressure for idler pump)
(3) Pressure tap (power shift pressure)
Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (2).
Illustration 2 g01429121
Pilot oil manifold
(28) Connector
(29) Swing parking brake (solenoid valve)
Disconnect connector (28) from solenoid valve (29).
Start the engine.
Place the machine controls at the following settings: engine speed dial "10" and AEC switch OFF. Reference: Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.
Move the swing joystick slowly and ensure that the swing parking brake is operating properly.
Illustration 3 g00764223
Swing motor
(22) Adjustment plug
(23) Locknut
(24) Relief valve (right swing)
Slowly move the swing joystick for a full SWING RIGHT operation and check the pressure for relief valve (24) at pressure tap (2).
Return the swing joystick to the NEUTRAL position.
The pressure gauge reading should be 24550 +1000 -2000 kPa (3550 +145 -290 psi). If the pressure gauge reading at pressure tap (2) is not within the specification, adjust relief valve (24) that is on the swing motor.
In order to adjust the swing relief valve, loosen locknut (23). Turn adjustment plug (22) until the pressure gauge reading at pressure tap (2) is 24550 +1000 -2000 kPa (3550 +145 -290 psi). Note: Turning adjustment plug (22) clockwise increases the pressure. Turning adjustment plug (22) counterclockwise decreases the pressure.Note: Always make final pressure adjustments on pressure rise.
Tighten locknut (23).
Illustration 4 g00764224
Swing motor
(25) Relief valve (left swing)
(26) Locknut
(27) Adjustment plug
Slowly move the swing joystick for a full SWING LEFT operation and check the pressure for relief valve (25) at pressure tap (2).
Return the swing joystick to the NEUTRAL position.
The pressure reading at pressure tap (2) should be 24550 +1000 -2000 kPa (3550 +145 -290 psi). If the pressure gauge reading is not within the specification, adjust swing relief valve (25).
In order to adjust the swing relief valve, loosen locknut (26). Turn adjustment plug (27) until the pressure gauge reading at pressure tap (2) is 24550 +1000 -2000 kPa (3550 +145 -290 psi). Note: Turning adjustment plug (27) clockwise increases the pressure. Turning adjustment plug (27) counterclockwise decreases the pressure.Note: Always make final pressure adjustments on pressure rise.
Tighten locknut (26).
After completing the test and/or the adjustment procedures for the swing relief valves, stop the engine.
Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".
Connect connector (28) to the solenoid valve for swing parking brake (29).