Komatsu PC200-8M0 Shop Manual page 215

403 Hydraulic system, Part 3
Travel motor
Operation of parking brake
1) When starting travel
q As the travel lever is operated, pressurized oil
from the pump activates counterbalance valve
spool (19), opening the parking brake circuit.
q The pressurized oil is conducted to chamber
(e) of brake piston (12) and compresses spring
(11), pushing piston (12) toward left.
Since the pushing force to plate (13) and disc
q
(14) disappears, plate (13) is separated from
disc (14) and the brake is released.
PC200, 200LC, 220, 220LC-8M0
SEN06121-00
17
10-403