Komatsu PC500LC-10R Shop Manual page 354

COMPONENT PARTS OF TRAVEL SYSTEM
When travel motor stops (parking brake is applied)
1.
When the travel lever is set to NEUTRAL, the counterbalance valve spool (14) returns to the neutral posi-
tion, and the parking brake circuit is closed.
2.
The pressurized oil in the chamber (e) of brake piston (20) passes through the throttle of slow return valve
(7) until the counterbalance valve spool (14) returns to the neutral position.
3.
When the counterbalance valve spool (14) returns to the neutral position, the oil is drained from the throttle
(f) of brake piston (20) into the case.
4.
The brake piston (20) is pushed to the left by spring (19).
5.
The plate (10) and disc (11) are pressed, and the brake is applied.
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10 STRUCTURE AND FUNCTION
PC500LC-10R
AEP20516