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| Illustration 1 | g00474332 |
Parking Brake Components (1) Actuator. (2) Parking brake. | |
Parking brake (2) is located in the drive line on the nonengine end of the machine. When the oil pressure in the brake system drops below a given pressure, actuator (1) engages the parking brake.
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| Illustration 2 | g00474333 |
Instrument Panel (3) Parking brake indicator. (4) Parking brake control knob. | |
The operator can also engage the parking brake by pulling out on parking brake control knob (4). Parking brake control knob (4) is located on the dashboard that is just to the right of the steering column.
A normally closed pressure switch is located on the parking brake control valve. The pressure switch signals the power train electronic control module (ECM), and the Caterpillar Monitoring System when the parking brake engages. When the parking brake engages, the switch activates parking brake indicator (3) on the dashboard.
The pressure switch also causes the transmission to shift into NEUTRAL position when the parking brake engages. The transmission is in either first speed FORWARD or first speed REVERSE.
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| Illustration 3 | g00474334 |
Front View Of The Parking Brake Control Assembly (1) Actuator. (5) Drum. (6) Yoke. (7) Shoes (two). (8) Brake assembly. (9) Rod. (10) Lever. (11) Shaft. (12) Cage. | |
The parking brake is a dry brake drum assembly. A spring engages the brake and oil disengages the brake. The spring is located in actuator (1). As drive shaft (11) rotates, drum (5), and yoke (6) also rotate. Brake assembly (8), and lever (10) are fastened to cage (12), which remains stationary.
When the parking brake is engaged, rod (9) moves lever (10) which will actuate brake assembly (8). Brake assembly (8) consists of three retraction springs and two brake shoes. The assembly is mounted on a plate assembly.
The brake assembly operates in the following manner. When lever (10) is actuated the plate assembly will expand. Shoes (7) inside brake assembly (8) press against drum (5). This prevents shaft (11) and yoke (6) from turning.