BACKUP RING 0693400 - Caterpillar

Illustration 3 g03602396
Stop valves for high-pressure oil delivery to the work tool (typical example)
Close the stop valves that are mounted on each side of the stick in order to prevent oil flow to the work tool during this procedure.
Disconnect the medium pressure lines for tool rotation and install the shipping plugs on the medium pressure lines. This action will prevent oil flow to the work tool for rotation during this procedure and allow for the valve to relief.
Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release" for the machine.
Illustration 4 g03628457
Medium pressure control valve
(1) Pressure tap (delivery pressure for the auxiliary pump)
Attach a 34,450 kPa (5,000 psi) pressure sensor to pressure tap (1). Temporary Setting of the Main Relief Valve
A temporary setting of the main relief valve is required before any line relief valves can be adjusted.
Move the control input to the full position for extension and retraction of the attachment control valve. Refer to Illustration 6 for the control inputs for tool rotation.
Check the main relief valve pressure setting at pressure tap (1).
Be sure that the main relief valve pressure is set