The elimination method of loader brake non-return position:
Loader in the process of driving, sometimes there will be driving weakness, a wheel brake disc smoke, burnt smell, then you can judge: brake clamp has locked phenomenon.
The wheel loader uses a double-tube air-push oil disc brake system. There are four points in the brake disc brake of the pump, two of which are opposed. When the brake pedal is pressed, the high pressure gas from the air compressor 1 pushes the gas piston of the gas-liquid master cylinder, and the gas piston pushes the oil piston. Brake fluid enters the piston chamber of brake disc brake cylinder through oil pipe and pushes the piston out; Piston drives friction disc brake, wheel brake.
There are four possibilities to cause the disc brake cylinder to fail to return: first, the foot brake valve 5 exhaust port is blocked, high pressure gas enters the human atmosphere, resulting in the gas-liquid master cylinder spring can not return, resulting in the brake oil disc brake cylinder piston can not return; Second, the gas-liquid master pump to the disc brake oil pipe blockage, resulting in the brake cylinder piston can not return to position; Third, the spring of the gas-liquid master cylinder itself can not return to the position, and the brake fluid can not return to the gas-liquid master cylinder oil storage chamber under the action of high pressure gas, resulting in the brake cylinder piston can not go back. Be returned; Four, disc brake cylinder piston brake fluid is too dirty or rusty piston stuck and unable to return.
When the fault is determined, first step on the foot brake valve, hear the exhaust sound after the pedal release, thus eliminating the first possibility. Then, the gas-liquid master pump is screwed to the disc brake cylinder pipe joint and the foot brake valve for several times, and it is found that there is brake fluid at the junction of the ejection, and the pressure is larger, which eliminates the second and third possibilities. Finally, we judge the brake cylinder failure.
The elimination method is to remove the brake disc fixing pin, remove the friction plate and dust ring, and reconnect the tubing joint. We wanted to push the piston out at high pressure with the brake fluid, but without success with the high pressure foot brake valve times, the split-pump piston 5 could neither return nor push out and became completely stuck. Then we remove the clamping cylinder head 6 and push the split piston out. It was then cleaned with diesel, sanded with 0# sandpaper, further cleaned and replaced with a new rectangular seal 2. Reinstall the test machine, the fault has been removed.
