SERV1851 02/08
- 219 -
Text Reference Travel System
TRAVEL PARKING BRAKE RELEASED
Drive Shaft
Retainer
Pump Supply
Housing
Barrel
Friction Plate Separator Plate
Head Piston Guide
Brake Piston
Brake Spring
Check Valve
173
Travel Parking Brake The travel parking brake is located in the travel motor. The travel parking brake consists of the following components: the brake spring, the brake piston, the separator plates, and the friction plates. The friction plates are splined to the cylinder barrel. The separator plates are splined to the motor housing. When the travel pedals or levers are moved from the NEUTRAL position, supply oil from the pump flows to the inlet port of the travel motor from the travel control valve in the main control valve group. A portion of the supply oil enters the motor and unseats the brake pilot check valve. The oil then flows to the brake piston. As pressure builds in the brake piston, the piston moves to the left against the brake spring. The separator plates and friction plates are no longer held together and the motor is able to rotate.
