When the vehicle runs, the brake pedal can not be brake immediately after stepping on the brake pedal, and the brake function is weak. The car will continue to slide and check the road.
    Face, tires are not towed or imprinted. There are the following reasons:
    the brake shoe friction plate is used for a long time, the wear is serious, or the driving in the mountain area, the brake is used frequently, the friction produces the high temperature, so that the friction is made.
The surface layer of the sheet was ablated and aged, and it was not changed in time.
During the riveting repair, the quality of the brake shoe friction plate is not good, the rivet is loosened and rocked; the brake clearance is adjusted unproperly or not in time.
    The brake drum is shedding sand stone grains or rivets, which causes the slots on the surface of the drum and sheet, the contact is bad, and the braking performance is reduced.
    The inner hole of the undercover of the brake shoe is large, so that the shoe is sinking and the clearance adjustment is difficult; or the brake shoe is supported to adjust the cam in the brake shoe.
    The inside corrosion card is stagnant, which hinders the adjustment of brake clearance and reduces the braking effect.
    The brake drum bearing nut adjustment too loose or too tight. When the vehicle is too loose, the vehicle is swaying, and the friction plate is in bad contact with the brake drum.
    When the bearing is too tight, the bearing is heated, the lubricating oil becomes thinner and dripping to the friction plate, causing slippery and brake soft fatigue.
The air compressor is not working, so that the air pressure in the storage cylinder is insufficient, the brake pipeline is leaking, the brake valve and other places are sealed without strict leakage;
    Pump skin bowl damage; air compressor string of oil, so that a large number of oil, do not enter the brake line, causing brake weakness.
    The brake pedal free travel is too large; the brake drum and gap adjustment of discomfort, loss of brake drum circle; worm adjusting brake arm.
    Improper, make the brake sub pump push rod extended too much, the compound brake valve balance spring block hair card, when braking internal and external balance spring movement interference and so on.