AFTERCOOLER AS 2108063 - Caterpillar

Illustration 1 g00931344
In the pilot hydraulic system, oil pressure is generated in the piston pump for the steering and pilot systems. The oil is directed to both the steering system and the pilot system. The oil that is directed to the pilot system will flow through a manifold and a pressure reducing valve. Next, the hydraulic oil flows through the solenoid valve (hydraulic lockout) for the pilot valve. The hydraulic oil flows through an inlet filter screen in the pilot valve.
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 connector for the return line, and the connectors of the lines which go to the end caps of the main relief valve.
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
AUXILIARYYou must pull 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) .On the 924Gz Wheel Loader, when you push the joystick control into the FLOAT position, the pilot oil pressure increases from about 1700 kPa (250.0 psi) to about 2750 kPa (400.0 psi). The increase in pilot oil pressure causes a pressure switch to close. When the pressure switch closes, the float solenoid valve is energized by electricity. Hydraulic oil in the lift circuit drains to the tank. The lift arms lower to the ground.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), pressure control return spring (24), and spring (28) keep lever assembly (13) in illustration 3 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