Repair and maintenance of drum brakes

Release time：

2023-05-18 09:21

Repair and maintenance of drum brakes
Repair and maintenance of drum brakes

A common repair for drum brakes is to replace the brake shoes. Some drum brakes have an inspection hole on the back that allows you to see how much material is left on the brake shoes. When the friction material has worn to the point where the rivet is only 0.8 millimeters long, the brake shoes should be replaced. If the friction material is bonded to the rear base plate (not with rivets), the brake shoes should be replaced when the remaining friction material is only 1.6 millimeters thick.

Similar to the situation in disc brakes, deep scratches can sometimes be worn out in the brake drum. If the worn brake shoes are used for too long, the rivets that fix the friction material at the rear will grind out grooves on the drum. Drums with severe scratches can sometimes be repaired by re polishing. Disc brakes have a small allowable thickness, while drum brakes have a large allowable diameter. Due to the contact surface being located inside the drum, the diameter will increase when you remove material from the drum brake.

maintain

When the pads are worn, more space will be created between the brake shoes and the drum. When the car comes to a stop during reverse, it will push the brake shoe to make it close to the drum. When the gap becomes large enough, the adjusting rod will shake enough to move the adjuster gear forward by one tooth. The regulator has a bolt like thread, so it can be loosened a bit during rotation and extended to fill the gap. Whenever the brake shoes wear a little bit, the adjuster will move forward a bit, so it always keeps the brake shoes and drum close together. Some car regulators will activate when using emergency brakes. If the emergency brake has not been used for a long period of time, the regulator may not be able to adjust again.

Therefore, if your car is equipped with such a regulator, you should use the emergency brake at least once a week.

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