MODULE 0R4045 - Caterpillar

Illustration 3 g00764560
Top view of the main control valve
(1) Relief valve (negative flow)
(2) Stick II control valve
(3) Line relief valve (boom cylinder head end)
(4) Boom II control valve
(5) Straight travel control
(6) Main relief valve
(7) Stick regeneration valve
(8) Swing priority valve
(9) Bucket control valve
(10) Line relief valve (bucket cylinder head end)
(11) Work tool control valve
(12) Boom I control valve
(13) Right travel control valve
(14) Left travel control valve
(15) Swing control valve
(16) Stick I control valve
(17) Line relief valve (stick cylinder rod end)
(18) Boom drift reduction valve
(19) Stick drift reduction valve
(43) Rear valve body
(44) Front valve bodyThe main control valves are located between the pumps and the actuators (cylinders and motors) in the hydraulic system. Depending on the machine operation, the oil flow from the drive pump, the idler pump, and the pilot pump to the hydraulic circuits are controlled by the operation of each component in the main control valve. These functions change the operating direction of the actuators and the speed of the actuators. These functions also limit the pressure within the hydraulic system.The main control valve consists of front body (44) and of rear body (43).
The following control valves are installed in parallel in front body (44):
Stick I control valve (16)
Swing control valve (15)
Left travel control valve (14)
Right travel control valve (13)
Boom I control valve (12)
Work tool control valve (11)
Bucket control valve (9)The following components are also installed in the front body.
Line relief valves
Line relief valve (21) for the rod end of the boom cylinder
Line relief valve (3) for the head end of the boom cylinder
Line relief valve (20) for the rod end of the bucket cylinder
Line relief valve (10) for the head end of the bucket cylinder
Line relief valve (23) for the head end of the stick cylinder
Line relief valve (17) for the rod end of the stick cylinder
Drift reduction valves
Boom drift reduction valve (18)
Stick drift reduction valve (19)
Load check valves (25)
The following control valves are installed in parallel in rear body (43):
Stick regeneration valve (7)
Boom II control valve (4)
Stick II control valve (2)The following components are also installed in the rear body.
Main relief valve (6)
Swing priority valve (8)
Straight travel valve (5)
Relief valve (1) and relief valve (22)
Orifice (31) and orifice (32)For further information of the components that are installed on the main control valve or in the main control valve, refer to the appropriate sections within this module.Main Control Valve Operation in NEUTRAL Position
Illustration 4 g01723234
Section view of the main control valve
(1) Front body
(2) Bucket control valve
(3) Work tool control valve
(4) Return passage
(5) Boom I control valve
(6) Center bypass passage
(7) Right travel control valve
(8) Left travel control valve
(9) Parallel feeder passage
(10) Swing control valve
(11) Stick I control valve
(12) Parallel feeder passage
(13) Center bypass passage
(14) Rear body
(15) Negative flow control orifice
(16) Stick II control valve
(17) Boom II control valve
(18) Inlet port
(19) Straight travel control valve
(20) Stick regeneration valve
(21) Swing priority valve
(22) Return port
(23) Negative flow control orifice
(24) Inlet portThe idler pump supplies oil through inlet port (24). The oil then flows through center bypass passage (13) and parallel feeder