PANEL AS 2234821 - Caterpillar

Illustration 1 g01646273
The parking brake in Released positionThe actuator for the parking brake (1) is attached to rear of the transmission.
Illustration 2 g01644856
Brake Actuator (1) Parking brake actuator (2) Spring chamber (3) Oil chamber (4) Oil port (5) Piston (6) RodThe brake actuator has two chambers, The spring chamber (2) and the oil chamber (3). When there is no oil pressure in the system the springs (2) cause piston (5) to move to the right and the parking brake will engage. When the parking brake switch is turned on the solenoid opens allowing the oil to flow into port (4). This will force springs (2) to compress. This moves rod (6), which disengages the parking brake. The parking brake will remain disengaged until the system oil pressure decreases allowing the spring to move to the piston and the rod right. When this happens the piston will move to the right.The pressure for the operation of the parking brake control is moved to the DISENGAGED position. The rod that activates the parking brake is in the DISENGAGED position when the switch is in the off position. When the parking brake switch is in the OFF position, the parking brake solenoid valve is open. This relieves the oil pressure behind piston (5). The parking brake piston (5) away from the springs (4). This moves rod (6) in order to engage the parking brakes.