BELT-SERPENTINE 3782561 - Caterpillar

Illustration 1 g01427928
Pump Compartment (1) Pressure tap (auxiliary pump) (2) Auxiliary pump
Illustration 2 g01454008
Open center valve (top view of boom foot) (3) Open center valve (4) Adjustment screw (main relief valve) (5) Pressure tap (medium pressure)
Install a pressure gauge with a 60000 kPa (8700 psi) capacity on pressure tap (5) for the medium pressure.
Start the engine.
Place the machine controls at the following settings: engine speed dial 10 and AEC switch OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for the machine for engine rpm settings.
Warm the hydraulic oil to 50 °C (122 °F).
Set the pilot pressure to the specifications in Testing and Adjusting, "Relief Valve (Pilot) - Test and Adjust" for the machine.
Calibrate the solenoid valves for medium pressure. Refer to Testing and Adjusting, "Medium Pressure: Solenoid Valve (Proportional Reducing) - Calibrate (Open Center Valve)" for the Tool Control System.
Set the auxiliary tool mode for medium pressure. Refer to Testing and Adjusting, "Work Tool - Select" for the Tool Control System.Note: To prevent oil flow to the work tool during this testing and adjusting procedure, close the stop valves in the lines for the work tool.
To adjust the pressure setting of the relief valve for medium pressure, press the device for activation for this procedure. Hold the device for activation in this position.Note: Relief action of the relief valve for more than ten seconds is not allowed.
Check the pressure at pressure tap (5) for medium pressure.
Return the device for activation to the NEUTRAL position.
Compare the pressure reading to the specification 14000 500 kPa (2030 73 psi). If the pressure reading is within the specification, no further adjustment is necessary. If the pressure reading is not within the specification, then proceed to Step 14.
The adjustment screw for the main relief valve is located on the side of valve (3) . Turn adjustment screw (4) until the pressure gauge reading at pressure tap (5) is 14000 500 kPa (2030 73 psi).Note: Turning adjustment screw (4) clockwise increases the pressure. Turning adjustment screw (4) counterclockwise decreases the pressure.Note: Always make final pressure adjustment on pressure rise.
Press the device for activation in the opposite direction. Hold the device for activation in this position.
Check the pressure at pressure tap (5) for medium pressure.
Return the device for activation to the NEUTRAL position.
Compare the pressure reading to the specification 14000 500 kPa (2030 73 psi). If the pressure reading is within the specification, no further adjustment is necessary. If the pressure reading is not within the specification, then proceed to Step 14.