GAUGE-PRESSURE 4C2972 - Caterpillar

Test Procedure
Prepare the machine for troubleshooting.ReferenceFor information about preparing the machine for troubleshooting, refer to the Service Manual module Troubleshooting, "Machine Preparation for Troubleshooting".The main relief valve is located on the main control valve. The main control valve is located in the loader frame under the loader tower access panel.
Illustration 1 g03825683
Main Control Valve (1) Main relief valve.
Illustration 2 g03825699
Main Control Valve (Auxiliary Function) (2) Main relief valve.
Start the engine and run the engine at high idle. Operate the control levers and move all the cylinders in order to increase the temperature of the hydraulic oil to normal operating temperature.
Illustration 3 g00384713
Lift Arm Supports
Lower the lift arms to the ground or to the stands. Turn the engine start switch to the OFF position.
Release the hydraulic system pressure. Refer to Testing and Adjusting, "System Pressure - Release".
Illustration 4 g00388155
Loader Tower Access PanelThe lift arms are raised for photographic purposes only.
Remove the loader tower access panel in order to access the main control valve.
Illustration 5 g03825705
Main Control Valve (3) Implement discharge pressure tap
Connect a 8T-0852 Pressure Gauge from the 1U-5481 Pressure Gauge Group to pressure tap (3) . Note: If the machine is equipped with a remote pressure tap, the tap will be located on a plate at the articulation joint.
Start the engine. Enter the Implement Hydraulic Service Mode.ReferenceFor additional information about this mode, refer to the Troubleshooting Testing and Adjusting, "Implement Hydraulic Service Mode" for the machine that is being serviced.
Move the work tool to the full RAISE position.Note: In the following steps, do not keep the lift control lever in the RAISE position for more than 5 seconds while the pressure is at the relief valve setting.
Increase the engine speed to high idle. Move the lift control lever to the full RAISE position. Observe the pressure gauge.The pressure setting of the main relief valve should be 20700 340 kPa (3000 50 psi).Note: If the pressure setting is correct, proceed to Step 14. If the pressure setting of the main relief valve is not at the specification, proceed with the following steps.
Illustration 6 g00819750
Main Relief Valve
Lower the work tool to the ground or lower the lift arms to the stands. Turn the key start switch to the OFF position before making any adjustments to the main relief valve.
Loosen locking nut (4) . Turn adjustment screw (5) clockwise in order to increase the relief valve setting. Turn adjustment screw (5) counterclockwise in order to decrease the relief valve setting.
After adjustment screw (5) is turned for an adjustment, tighten locking nut (4) to a torque of 50 7 N m (37 5 lb ft).
Repeat Step 10 through Step 12 until the main relief valve is correctly adjusted.
After the pressure setting is correctly adjusted, lower the lift arms to the ground or to the stands. Turn the key start switch to the OFF position.
Remove the test equipment. Install the loader tower access panel on the machine.
Start the engine and remove the lift arms from the stands. Ensure that the work tool is on