WASHER, 5/16" HALF RD. F120298 - Caterpillar

Do not engage the parking brake while the machine is moving unless the primary service brake fails. The use of the parking brake as a service brake in regular operation will cause severe damage to the parking brake system.
Illustration 1 g00932141
Parking Brake Components for the 14H Motor Grader (1) Air control valve for the parking brake (2) Parking brake solenoid valve (3) Parking brake actuator (4) Parking brake check valve (5) Quick-release valve
Illustration 2 g00932326
(6) Transmission control (lever)A disc type brake in the front part of the transmission housing is used as the parking brake. Parking brake actuator (3) on the side of the transmission activates the parking brake. The parking brake is released by air. The parking brake is applied by a spring.When transmission control (lever) (6) is depressed and the transmission control (lever) is moved backward, parking brake solenoid valve (2) is activated. This allows pressure air to flow through parking brake check valve (4). The pressure air then flows through air control valve (1) for the parking brake.
Illustration 3 g00932168
Section View of Parking Brake (7) Springs (8) Discs (9) Cage (10) Output flange (11) Coupling (12) Housing (13) Plates (14) Plunger (15) Piston (16) Inserts (17) BallsPressure air from air control valve (1) for the parking brake flows through quick-release valve (5) into parking brake actuator (3). The pressure air moves the rod and the rod end of the parking brake actuator. The rod end is connected to a lever on the front of the transmission housing. This lever is connected to piston (15) in the transmission. As the parking brake actuator moves the rod end and the lever downward, the piston turns in order to release the disc type brake. Parking brake check valve (4) prevents the parking brake from disengaging if the air pressure to the air control valve for the parking brake is low.When transmission control (lever) (6) is moved to the PARKING BRAKE ENGAGED position, air pressure is not allowed to flow through air control valve (1) for the parking brake. The exhaust port of quick-release valve (5) opens in order to release the air in parking brake actuator (3). Without pressure air in the parking brake actuator, the spring force moves the rod and the rod end upward. This action moves the lever on the transmission housing in order to engage the parking brake.When transmission control (lever) (6) is in the PARKING BRAKE ENGAGED position, no pressure air is available to parking brake actuator (3). The spring in the parking brake actuator moves the rod in the parking brake actuator. The rod end moves the lever on the transmission housing upward. This turns piston (15). As the piston turns, balls (17) move up the taper of inserts (16). The piston comes into contact with plates (13) and discs (8). The piston pushes the plates and the discs against cage (9). The cage is connected to housing (12). As the friction between the plates and discs becomes greater, coupling (11) stops moving. The machine