SPROCKET 1554407 - Caterpillar

Hydraulic Schematic for the Main Control Valve
Illustration 1 g01364052
(1) Pilot manifold (2) Proportional valve for left travel (reverse) (3) Proportional valve for right travel (reverse) (4) Solenoid valve (neutral bypass) (5) Main control valve (6) Neutral flow control valve (7) Left travel control valve (8) Right travel control valve (9) Differential relief valve (10) Signal relief valve (low pressure) (11) Signal relief valve (high pressure) (12) Solenoid valve (high/low relief) (13) Differential relief valve (14) Return port (15) Inlet port (rear pump) (16) Inlet port (front pump) (17) Return port (18) Proportional valve for left travel (forward) (19) Proportional valve for right travel (forward) (20) Hydraulic tank (21) Front pump (22) Rear pump (23) Pilot pump (24) Fan pump (25) Swing pumpIntroduction
The main control valve is located in the hydraulic circuit between the main pumps, and the cylinders and travel motors. The oil flow from front pump (21), rear pump (22), and pilot pump (23) is controlled by the operation of each component in the main control valve. Through this control, the direction and speed of the cylinders and the motors can be adjusted. This control also limits the pressure of the supply oil.
Illustration 2 g01364258
Main Control Valve (Top View) (2) Proportional valve for left travel (reverse) (3) Proportional valve for right travel (reverse) (4) Solenoid valve (neutral bypass) (6) Neutral flow control valve (12) Differential relief valve (13) Signal relief valve (low pressure) (14) Signal relief valve (high pressure) (15) Solenoid valve (high/low relief) (16) Differential relief valve (17) Return port (20) Return port (21) Proportional valve for left travel (forward) (22) Proportional valve for right travel (forward) (29) Main control valve body (right side) (30) Center manifold (31) Main control valve body (left side)
Illustration 3 g01364296
Main Control Valve (26) Main control valve (right body) (27) Center manifold (28) Main control valve (left body)The main control valve consists of right body (26), left body (28), and center manifold (27) .
Control valves are arranged in parallel in the right side of body (26). The pump oil is delivered through return port (14) to hydraulic tank (20) .
When the control levers are in the NEUTRAL position, neutral flow control valve (6) and solenoid valve (4) deliver the return oil in the main control valve to hydraulic tank (20) .
Left travel control valve (7), and right travel control valve (8) are located in the left side of body (28). The pump oil is delivered through return port (17) to hydraulic tank (20). In addition, the following components are located in the stick side of the body:
A proportional valve is located at the end of each stem in the left side of the main control valve body. Pilot oil pressure flows to each proportional valve in order to control the stem movement in the main control valve. Pilot oil pressure is controlled at the main control valve by the following proportional valves: proportional valve (2) for the left travel (reverse), proportional valve (3) for the right travel (reverse), proportional valve (18) for the left