Komatsu ecot3 PC300LC-8 Shop Manual page 228

SEN01995-01
Operation of parking brake
1) When starting travel
q As the travel lever is operated, pressurized oil
from the pump activates counterbalance valve
spool (17), opening the parking brake circuit.
q The pressurized oil is conducted to chamber
(a) of brake piston (10) and compresses spring
(9), pushing piston (10) toward right.
q Since the pushing force to plate (11) and disc
(12) disappears, plate (11) is separated from
disc (12) and the brake is released.
36
10 Structure, function and maintenance standard
PC300, 350-8