Operation & Maintenance Manual
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LG936L Wheel Loader
115
When the brake pedal is stepped on during driving, the compressed air in air tank 5 flows through air
brake valve 6 into the air chamber of the air booster valve 7. The compressed air pushes the piston of
the booster pump to change the oil pressure (oil pressure is about 14MPa). Brake fluid pushes the
piston of the caliper disk brake and makes the friction disk contact the brake plate to achieve the
purpose of slowing and braking.
Release the brake pedal, and the compressed air of the booster pump drains from the brake valve to
the atmosphere and the brake is released.
3.2 Driving Brake System(Single Brake Pedal):
As shown in Figure 5-6, this system is the double brake pedals, air pushing oil four wheels caliper
disk brake system using two brake calipers for front and back to increase the safety of whole vehicle.
When the left brake pedal is stepped on during driving, the compressed air in air tank 4 flows through
air brake valve 3 and shuttle valve 2 into the air chamber of the air booster pump 1. The compressed
air pushes the piston of the booster pump to change the oil pressure (oil pressure is about 14MPa).
Brake fluid pushes the piston of the caliper disk brake and makes the friction disk contact with the
brake plate to achieve the purpose of slowing and braking. The air pressure is outputted at the same
time to cut off the power of gear box.
When the right brake pedal is stepped on during driving, the brake principle is the same as left brake
pedal, but the power of transmission box is not cut off.
Release the brake pedal, and the compressed air of the booster pump drains from the brake valve to the atmosphere
and the brake is released.
3.3 Parking Brake System
This system employs two different forms: the total hydraulic clamping disc braking system and the
total hydraulic pin steering system. During driving, when the pressure of air in brake system is in
normal level, rotate the operating button of brake electromagnetic valve slightly, the button will
bounce out automatically, and then the compress air in the air tank through the brake magnetic valve
to the parking brake air chamber to pull the plug away and release the brake. When stopping, press
the operating button of brake magnetic valve, the compress air in the parking brake air chamber
through the air draining port of brake magnetic valve to aerospace. Then the brake is pulled up under
the spring to arrive to brake. At the same time, send an electric signal to turn on the parking brake
indicator, by which to alarm the operator that the vehicle is in the braking condition.
When the system air pressure is lower than 0.4Mpa, the brake magnetic valve will cut off
automatically to control the compress air in the parking brake air chamber to drain into the aerospace
by hand, so that the emergency brake is utilized to protect the safety of vehicle and people.