Operation & Maintenance Manual
──
LG958L/LG959 Wheel Loader
115
3.1 Driving Brake System (Single Brake Pedal)
As shown in Figure 5-3, this system is the single line, 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 brake pedal is stepped on during driving, the compressed air in air tank 3 flows through air
brake 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 the brake plate to achieve the
purpose of slowing and braking.
In this time, turn on the select switch of cutting power. At the same time output the signal of air
pressure and cut off the power of transmission box. In some specific conditions (ramp operation), the
power of transmission box is not cut off, which is 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 (Double Brake Pedals)
As shown in Figure 5-4, 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 (the max 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. At the same time, send an air pressure
signal and cut off the power of transmission 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 Emergency and Parking Brake System
This system employs the electric air control inside shoe brake system. During driving, rotate the
operating button of brake magnetic 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
