Hyundai HX145LCR Manual page 127

3) 3) WORKING OF PARKING BRAKE WORKING OF PARKING BRAKE
Parking brake system consists of a brake piston, springs, friction plates and separating plates, and
some orifices to control responsibility of the brake piston. The brake is usually held with the force of
compressed spring, and it is released automatically by traveling oil pressure coming from inlet A, or
B when the motor starts to run.
• •
Parking brake OFF Parking brake OFF
When operator moves the traveling control lever, traveling working pressurized oil into IN PORT
flows from spool chamber through counter orifice.
Pressurized oil pushes counter balance spool to right.
Then notch of spool opens the brake line. At the same time, pressurized oil flows to the brake
chamber of motor through a brake passage, and makes brake piston move against brake spring
force to allow clearance between fiction plates and separate plates thereby releasing the brake.
Brake Brake
Brake Brake
piston piston
chamber chamber
Friction plate Friction plate
SECTION C-C"
Counter
chamber
Brake Brake
spring spring
orifice
Spool
Brake fluid pressure way
C
A Port
(IN Port)
C"
2-75
B Port
(OUT Port)
145Z9A2TM08