Repair and maintenance of commercial vehicle brake drums

Automobile braking relies on the friction between the brake drum and the brake shoe friction plate to generate braking force to slow down or stop the vehicle. The long-term use of commercial vehicle brake drums can cause a certain degree of wear or strain. Therefore, the maintenance and repair of the brake drum is very important.

When maintaining the commercial vehicle brake drum, when the roundness deviation of the commercial vehicle brake drum exceeds 0.25mm, there are deep grooves on the working surface, and the deviation from the wheel hub bearing line exceeds the regulations, boring should be carried out. When boring the brake drum, the commercial vehicle brake drum should be installed together with the wheel hub, and positioned with the outer race of the inner and outer wheel hub bearings. Boring can be carried out on specialized equipment or lathes. The cylindricity deviation of the brake drum after frying should not exceed 0.075mm, and the coaxiality deviation with the automotive wheel hub axis should not exceed 0.025mm. The size difference between the left and right wheel brake drums should be less than 1mm, and the inner diameter should not exceed the allowable larger repair size. During inspection, if cracks are found on the brake drum or if the inner diameter exceeds the allowed larger repair size, it should be replaced.

Commercial vehicle brake drum manufacturers share maintenance suggestions:

1. Strengthen the inspection of safety hazards before and during transportation, especially the technical application of braking, steering, transmission, and wheel parts, to ensure safe and reliable operation.

2. During the operation of a car with a cooling brake drum, as the temperature of the commercial vehicle's brake drum increases, the braking efficiency will significantly decrease. Therefore, the car is equipped with a water reservoir. Before going downhill, turn on the water reservoir switch to let it pour water onto the outer surface of the brake drum to cool down, which can reasonably improve braking efficiency.

3. Scientific driving allows for segmented driving when encountering relatively long downhill slopes and particularly sharp curves. After running for a distance, find a slightly gentle slope and a good view of the front, rear, left, and right to stop. This not only allows the air reservoir to be fully inflated, but also cools down the brake drums and shoes of commercial vehicles before driving.

4. Most cars that use high-quality brake fluid for hydraulic braking use alcohol based brake fluid, which contains alcohol that is easily volatile. Frequent braking can easily cause an increase in the temperature of the braking pipeline, resulting in air resistance and brake failure. If high-quality brake fluids with high boiling points and low risk of deterioration are used, driving safety performance can be greatly improved.

5. Correctly brake and apply the drag action of the engine and foot brake to control the speed. It is forbidden to step on the clutch pedal or slide in neutral, and emergency braking is avoided.