How to adjust the brake shoe clearance

There must be a certain gap between the brake shoe and the brake drum, and the gap between the shoes is not satisfactory, which will directly affect the braking performance of the car. The gap between the shoes is too large, which makes the brake lag time increase, the braking distance increases, and the safety of the vehicle is reduced. The gap between the shoes is too small, so that the brake can not be completely removed, the driving resistance is increased, and the brake drum is accelerated. Wear of the shoe. The brake shoes of each wheel are inconsistent, and the brake deviation will occur, which also affects driving safety. Therefore, the shoe gap should be handled after the vehicle is being serviced, the shoe is updated, and the brake is repaired.
Make an inspection adjustment.
1 Adjustment of air brake shoe clearance
The adjustment of the brake shoe clearance is divided into simple adjustment and comprehensive adjustment. Only by turning the adjustment worm to change the gap of the shoe, called simple adjustment
Through the adjustment of the adjustment arm worm and the fulcrum pin, the requirements for the gap of the shoe are achieved, which is called comprehensive adjustment. In the usual use of the vehicle, only simple adjustment can be achieved, but when the simple adjustment can not meet the requirements, it should be fully adjusted.
The adjustment of the gap of the shoe must be carried out after the tightness of the hub bearing is adjusted.
1) Easy adjustment
1 set up the axle to allow the wheels to rotate freely.
2 Check the gap at the upper and lower ends of the shoe with the specified thickness gauge.
3 Turn the worm on the brake arm as shown in Figure 2. Adjust the upper end clearance, the front wheel rotates the worm clockwise, the gap becomes smaller, and vice versa; the rear wheel rotates the worm counterclockwise, the gap becomes smaller, and vice versa. When adjusting, repeatedly pull the thickness gauge when feeling a slight resistance
When it is appropriate. When the gap is adjusted, it is found that the friction plate and the brake drum still have a slight friction sound, allowing the gap to be slightly enlarged.
2) Comprehensive adjustment
1 Add the axle to make the wheel rotate freely.
2 Rotate the locking screw of the loose-shoe hoisting pin. Turn the fulcrum pin so that the lower end of the shoe is close to the brake drum. Then turn the brake arm to adjust the worm so that the upper end of the shoe approaches the brake drum. Repeat the adjustment until the upper and lower ends of the two shoes are in full contact with the brake drum, and the brake drum cannot be rotated.
3 Turn the brake arm to adjust the worm so that the friction plate is out of contact with the brake drum, a gap appears, and the gap between the upper and lower ends is checked with a thickness gauge. The following end gap is not suitable, you can slightly rotate the fulcrum pin a little, and the upper and lower fits until the gap meets the requirements.
4Lock the fulcrum pin fixing nut.
In the actual adjustment process, there is a case where the gap is large and the gap is small. At this time, for the front wheel brake, the three fixing screws on the camshaft bracket can be loosened. For the rear wheel brake, the fixing screws on the brackets at both ends of the camshaft can be loosened, and then the camshaft is used to punch the camshaft to the gap. The big side is close. If this is not effective, an iron sleeve can be placed on the contact portion of the hoof and the cam with a large gap, and iron sheets of different thicknesses can be inserted into the iron sleeve for adjustment.