Komatsu PC88MR-10 Shop Manual page 189

Swing parking brake
Operation
Solenoid valve is "de-energized"
When the swing parking brake solenoid valve is de-energized, the pressurized oil from the charge pump is
blocked.
Port (B) is connected to tank circuit (T).
Brake piston (2) is pushed up by brake spring (1).
Discs (3) and plates (4) are pressed and the brake operates.
PC88MR-10
(PC88MR-J6A0-044-K-00-A)
10 Structure and function
Swing motor
10-111