MOUNT 4802754 - Caterpillar

Illustration 1 g00931344
Illustration 2 g00931349
Note: The pilot valve in Illustration 2 is for machines with an auxiliary function. Machines without an auxiliary function will not have auxiliary valve (10) .The pilot oil enters the implement joystick at the pilot pressure inlet (6). Illustration 2 shows the position of the pilot pressure inlet, the return line connector, and the line connectors to the main relief valve end caps.
Illustration 3 g00930998
The joystick controls the pilot oil. The pilot oil controls the movement of the spools in the main control valve. When the hand lever is moved, lever assembly (13) will rotate. Adjustment pin (14) will push down on the upper plunger (17).
Illustration 4 g00931000
The joystick control is equipped with detent coils. When you start the engine, the detent coils are energized by electricity. Four positions can have detent coils.
TILTBACK
RAISE
FLOAT
AUXILIARYPull the FLOAT and AUXILIARY levers out of the detent position by hand.When the joystick control is rotated to 90 percent of lever travel, retainer (15) contacts detent coil (20). Detent coil (20) will hold retainer (15). The joystick will be held in position until the kickout switch interrupts the flow of current to the detent coil. The detent coil de-energizes and lever assembly (13) can return to the HOLD position. Plunger (12) initiates a force against cup (16) in order to assist the spring in pulling retainer (15) from detent coil (20) .The flow of pilot oil through the system is controlled by the cartridge assembly. The movement of each spool in the main control valve is determined by the individual cartridge assembly. The location of the cartridge assembly is shown in Illustration 3. The following sections explain the operation of the cartridge assembly.The Cartridge in the HOLD Position
Illustration 5 g00931358
When the cartridge assembly is in the HOLD position, centering spring (18), spring (24), and spring (28) keep lever assembly (13) in the HOLD position.Pilot pressure oil flows into the joystick control through the port at the bottom of the valve. The pilot oil flows through pilot oil passage (31) in illustration 3. The passage takes the oil to port (29) of the cartridge assembly.The position of spool (23) blocks port (29). The pilot oil is prevented from flowing into ports (25) and (26). The internal passages are open to return port (25). This passage drains the pilot lines from the main control valve to return port (25). Return port (25) provides a path back to the hydraulic oil tank. Illustration 5 shows the flow of pilot oil through the cartridge assembly in the HOLD position.Spring (28) will help to push up the spool. In the HOLD position, oil flows through hole (32) and through the center of spool (23). The oil flows into chamber (33). The oil is held in the chamber until the spool is moved.The Cartridge with an Activated Spool
Illustration 6 g00931372
In order to move a work tool, the flow of oil in the main control valve must be routed to a cylinder. This flow of oil is accomplished by sending pilot oil from