1. Disassembly of the main control valve assembly
① Lower the working device to the ground and stop the engine.
②The excavator operates the joystick and pedal several times to depressurize the hydraulic pipeline.
③ Slowly loosen the air breather on the fuel tank to relieve the pressure. Pay attention to prevent the residual liquid from being splashed by the pressure to burn the skin.
When the pipe and hose are disconnected, the oil in the pipe flows out, and the oil that flows out is placed in the container
④Remove the bolts and disconnect the piping, as shown in Figure 3-38.
⑤ Disconnect the pilot hose, as shown in Figure 3-39.
⑥ Disconnect the servo hose, as shown in Figure 3-40
⑦ Lift up the control valve assembly and remove the mounting bolts on the control valve
⑧ Remove the control valve assembly. When removing the control valve assembly, check that all hoses have been disconnected.
2. Installation of main control valve assembly
① Install in the reverse order of removal.
②Exhaust air from the cylinder (boom, arm, bucket), swing motor and travel motor
