GROMMET 1966184 - Caterpillar

Illustration 5 g03627277
Main relief valve (standard)
(A) Adjustment screw
(L) Locknut
Illustration 6 g03627279
Main relief valve (heavy lift)
(A) Adjustment screw
(L) Locknut
Loosen the locknut. Turn the adjustment screw clockwise for one half turn. Tighten the locknut.
Reset main relief valve pressure setting to the normal operating condition after the completion of the line relief test and adjust. Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust" for the machine. Test Procedure
Start the engine.
Select a work tool to meet the following conditions.
Two-way flow
Variable relief valve pressure set at the default specifications of 40,000 kPa.Refer to Testing and Adjusting, "Work Tool - Select" for the Tool Control System.
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 engine rpm settings.
Increase the hydraulic oil temperature to 50° 10°C (122° 18°F).
Illustration 7 g02292254
Control Inputs for attachment control valves extended.
(LJ) Left-hand joystick
(RJ) Right-hand joystick
(A) Thumb wheel (Forward)
(A) Switch
(FP) Electric foot pedal
(A) Pedal (Forward)
(FS) Foot switch
(A) Foot switch (ON)
Illustration 8 g02292257
Control Inputs for attachment control valve retracted.
(LJ) Left-hand joystick
(RJ) Right-hand joystick
(B) Thumb wheel (Backward)
(FP) Electric foot pedal
(B) Pedal (Backward)
Operate the control input in the appropriate direction in order to relieve the valve. Note: A continuous relief of the valve for more than 10 seconds is not allowed.
Check the main relief valve pressure setting at pressure tap (1) or pressure tap (2). Refer to Table 2 for the pressure specifications of the line relief valves.
Return the joystick to the NEUTRAL position. Adjustment Procedure
Attachment Control Valves Extend
Illustration 9 g03635676
Line relief valve for extension of the attachment control valves
To adjust the line relief valve pressure setting, operate the control input for extension of the attachment control valves to the FULL position and hold. Refer to Illustration 7 for the control input.
Check the pressure reading at pressure tap (1).
Return the control input to the NEUTRAL position.
The pressure reading should be within the specification. Refer to Table 2. If the pressure reading at pressure tap (2) is not within the specification, adjust the line