BOSS 9T3598 - Caterpillar

Illustration 1 g00432798
Pilot Valve In the HOLD Position (1) Pivot plate (2) Detent balls (two) (3) Plunger assembly (4) Plunger assembly (5) Magnetic detent (6) Magnetic detent (7) Retainer (8) Retainer (9) Spring (10) Magnetic detent (11) Centering springs (12) Passage to tank (13) Springs (14) Metering stem (15) Metering stem (16) Work port (17) Port for pump oil pressure (18) Work port (A) REVERSE position (B) HOLD position (C) First FORWARD position (D) Second FORWARD positionWhen the pilot control valve is in HOLD position (B) , spring (9) , springs (13) and detent balls (2) keep pivot plate (1) in the center position. Springs (13) hold metering stem (14) and metering stem (15) up so work port (16) and work port (18) are vented to the hydraulic tank. There are orifices in work port (16) and work port (18) . These orifices provide stability in the valve group.When the pilot control valve is in first FORWARD position (C) , pivot plate (1) causes plunger assembly (4) to move down. Plunger assembly (4) will retract springs (11) and springs (13) . This will allow metering stem (15) to shift. Then, the oil from pump port (17) will flow out of work port (18) . Retainer (7) is forced upward by spring (9) . Magnetic detent (5) holds retainer (7) in this position. This position is maintained until the control lever and pivot plate (1) are manually moved to the HOLD position (B) . Oil pressure in work port (18) is 1200 100 kPa (175 15 psi) .When the valve is in second FORWARD position (D) , pivot plate (1) causes plunger assembly (4) to move downward. Plunger assembly (4) will retract springs (11) and springs (13) . This will allow metering stem (15) to shift. Then, the oil flows from pump port (17) out of work port (18) . Retainer (8) is forced down by plunger assembly (4) . Magnetic detent (10) holds retainer (8) in position. This position is maintained until