PLATE-CAM 7I1084 - Caterpillar

Illustration 1 g01219928
Pilot valve (left side view)
(1) Boot. (2) Lever assembly. (3) Detent plate. (4) Cartridge assembly. (5) Body. (6) Detent coil.
Illustration 2 g01206274
Right side view of cab
Location of pilot valve
The pilot valve controls the pilot pressure to the main control valve. The main control valve controls the flow of oil to the lift cylinders and tilt cylinders.In the pilot hydraulic system, oil is supplied by the pilot/brake pump. The oil is directed to the combination valve. Once pilot pressure is obtained, the oil is directed back to the tank. The pilot oil is directed to the pilot accumulator in order to charge the accumulator. Pilot oil is then directed to the solenoid valve (hydraulic lockout) for the pilot valve. The pilot oil is then directed to the pilot valve.
Illustration 3 g01206279
Base of pilot valve
(7) Control port for TILT RIGHT position. (8) Tank port. (9) Control port for LOWER position or FLOAT position. (10) Control port for TILT LEFT position. (11) Pilot supply port. (12) Control port for RAISE position.
The pilot oil enters the implement joystick at the pilot pressure inlet (11). Illustration 3 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. The blade control lever controls the pilot oil. The blade control lever is connected to lever assembly (2) by a rod. When the blade control lever is moved, the lever assembly will push down on the top of cartridge assembly (4). The spool in cartridge assembly (4) controls the flow of oil to the control ports in the base of the valve.The joystick control is equipped with detent coil (6). When you start the engine, the detent coil is energized by electricity. Only the FLOAT position has a detent coil.When the joystick control is rotated to 90 percent of lever travel, the retainer on the lever assembly contacts detent coil (6). Detent coil (6) will hold the retainer. 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 can return to the HOLD position.When you push the joystick control into the FLOAT position, the pilot oil pressure increases to maximum pilot system pressure. The increase in pilot oil pressure causes the lift spool in the main control valve to shift into the FLOAT position. Hydraulic oil in the rod end of the lift cylinder and the head end of the lift cylinder 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 1. The following sections explain the operation of the cartridge assembly.The Cartridge in the HOLD Position
Illustration 4 g01206295
Cartridge assembly
(13) Spring. (14) Hole. (15) Port. (16) Port. (17)