PLATE 3712329 - Caterpillar

SELECTOR BRAKE CONTROL VALVE
3-Actuator assembly. 4-Plunger. 5-Valve seat. 6-Plate. 7-Valve. 8-Air chamber. 9-Plate. 10-Air chamber. 11-Valve. 12-Valve seat. 13-Delivery port. 14-Exhaust port. 15-Delivery port. 16-Drilled passages.When the control handle moves clockwise the valve plunger moves to the right actuating the valve (7) in a similar manner. Pressure air passes from the air chamber (10) through the delivery port (15) to the right brake chamber applying the right brake. The delivery port (13) to the left brake chamber remains open to atmosphere through drilled passages and the exhaust port.Differential Lock Valve
The differential lock valve controls the supply of air to the differential lock air chamber and to the control port of the pilot valve. Depressing the pedal moves spool (1) down unseating check valve (4) and allows air to flow from supply port (5) out through the delivery port (3) to the locking air chamber and the pilot valve. Releasing the pedal allows the valve to return, sealing supply port (5) and allowing air to flow from the air chamber and pilot valve out through exhaust port (2). The operation and construction of the transmission holding valve is similar.
DIFFERENTIAL LOCK VALVE
1-Spool. 2-Exhaust port. 3-Delivery port. 4-Check valve. 5-Supply port.Differential Lock Valve (Early Machines)
The differential lock valve controls the supply of air to the air chamber for the differential lock and to the selector brake. Depressing the pedal moves the spool (2) allowing air to flow from supply port (4) out through the delivery port (3) to the locking air chamber. Air is exhausted from the air chamber and the selector brake through delivery port (5) to the exhaust port (1). Releasing the pedal allows the spool (2) to return, air from delivery port (3) is now exhausted through port (1). Air from the supply port (4) then flows through delivery port (5) to the selector brake and to the air chamber unlocking the differential.
DIFFERENTIAL LOCK VALVE (EARLY MACHINES)
1-Exhaust port. 2-Spool. 3-Delivery port. 4-Supply port. 5-Delivery port.Pilot Valve
The pilot valve controls the flow of air to the selector brake and prevents application of the selector brake with the differential locked. Air for the selector brake and differential lock release flows into supply port (5) and out through delivery port (4). When the differential lock valve is actuated, air from the differential lock valve is directed to control port (3). The air pressure from the control port raises spool (1) and causes supply port (5) to be blocked. The delivery port (4) is opened to exhaust port (2).
PILOT VALVE
1-Spool. 2-Exhaust port. 3-Control port. 4-Delivery port. 5-Supply port.Hydraulic Retarder Control Valve
The retarder air control valve controls the braking capacity of the retarder by metering air pressure to the retarder control group. The distance the air control valve handle is moved in a clockwise direction, toward applied position, the greater the braking capacity of the retarder.As the control handle (2) is moved toward the applied position, the head (1) and cam follower (3) are rotated, exerting a force on top of the pressure