The main control valve is situated in the hydraulic circuit between the main hydraulic pump and the implement cylinders, the travel motors, and the swing motor. The main hydraulic pump supplies high-pressure hydraulic oil to the main control valve. Pilot pressure oil from the pilot manifold is used to by the ECM to command the movement of nine primary valve spools in the main control valve. The nine primary valve spools, in turn, control the flow of the high-pressure oil to the implement cylinders and motors. The main control valve determines the direction and speed of the implement cylinders and motors in proportion to the movement of the operator joysticks and travel lever/pedals. The nine primary valve spools control the following components:
- Boom cylinders (RAISE and LOWER)
- Stick cylinder (IN and OUT)
- Bucket cylinder (OPEN and CLOSE)
- Auxiliary system (SUPPLY and RETURN)
- Swing boom cylinder (LEFT and RIGHT) (If Equipped)
- Variable angle boom (VAB) (LEFT and RIGHT) (If Equipped)
- Power offset boom (POB) (RAISE and LOWER) (If Equipped)
- Swing motor (LEFT and RIGHT)
- Left travel motor (FORWARD and REVERSE)
- Right travel motor (FORWARD and REVERSE)
- Blade cylinder (RAISE and LOWER)
Note: Refer to the appropriate sections in this manual for more information.