Recently, I heard that many friends will have such problems. Many car owners have abnormal brake noise within a few days after they have completed maintenance and replacement of brake pads. Some car owners may not notice the abnormal noise because it is relatively slight, while some abnormal noise is more obvious, which makes car owners think that there is some new problem with the newly replaced brake, resulting in the trouble of returning to the factory for testing again.

When it comes to abnormal brake noise, it's not just in cars. For road bicycles and motorcycles, the abnormal noise of brake pads is also often encountered and occurred on these two models. Then why the new brake pads are prone to abnormal noise? This is from the design of the brake itself.

Disc brake device

At present, the mainstream of passenger cars in the market uses disc brakes, which are composed of brake discs and brake calipers. The brake disc is shaped like a turntable, also made of metal, and rotates coaxially with the wheel. The brake caliper is fixed and does not rotate, and it spans both sides of the brake disc to form a "caliper type". During the braking process, the driving mechanism urges the brake caliper to clamp the two sides of the brake disc, and the brake pads inlaid on the caliper violently rub the brake disc, forcing its speed to decrease until it stops.

Poor contact of brake pads

The wear between the brake disc and the brake pad is definitely not uniform, because the material used for the brake pad is not a pure metal block, but a metal-carbon-ceramic mixture, which is fired into one body under high temperature and high pressure, and the surface is smooth, so the brake The grinding of the disc is uneven and grooves appear.

When new brake pads are replaced, because the new brake pads are flat and smooth, poor contact will occur when they come into contact with brake discs that already have fine grooves. The raised part on the brake disc surface is in contact with the brake pad, so the contact area between the two will become smaller, and the braking effect will deteriorate and abnormal noise will occur.

Grinding brake pads

For the problem of abnormal noise of new brake pads, masters can mention a mouth to the technician when replacing the brake pads. It is required to polish the brake pads before loading and round the chamfer on the brake pads a little. Make the brake pads out of contact with the outermost side of the brake disc surface, so that the abnormal noise can be solved.

Grinding brake disc

For this method, the editor is generally not recommended to do it. Specifically, polishing the brake disc is commonly known as "disc". It is to remove the brake disc and fix it on the milling machine, and scrape off all the grooves on the disc surface with a milling cutter. Generally, the disc player is 50-100 wires (1 wire = 0.01mm) at a time, while the thickness life of the general brake disc can only support one such "planing" operation at most.

For brake pad polishing, the technician will polish off the oxide layer and chamfer on the new brake, which will affect the service life of the brake pad to a certain extent. Generally, the service life of brand-new brake pads is about 4-50000 kilometers, and technicians running in the brakes in advance will reduce the life of the new brake pads. For example, the original brake pads can run 40000 kilometers, but now they can only run 37,000 kilometers.

For brake disc discs, scraping off a layer of disc surface will cause errors in the local weight of the original brake disc. The brake disc is no less sensitive to dynamic balance than tires. The low tolerance of thickness tolerance cannot exceed 0.3 ounces, and the lateral runout cannot exceed 0.15 ounces. This tolerance cannot be recognized by the naked eye. But it is because of such a low tolerance, it can ensure that when the disc and sheet are operating at high speed, there is an effective reduction in noise and no jitter performance. Therefore, it is recommended that you replace the brake disc.

Phone/WhatstApp: 
+86-17531828113
+86-15165025890

E-mail: 
ls8203996@gmail.com
xl227318@gmail.com

Address:
Hebei Province Hengshui Gucheng County High-tech Development Zone Pioneer Park