After the brake pads are worn out, the brake discs are also worn. Must the brake discs be replaced
We all know that the brake pads must be replaced when they are worn out. However, if the brake pads are worn out and are not found in time, the brake discs will also be worn out. The brake pad is fixed on an iron plate. When the brake pad is worn out, the iron plate will rub against the brake disc. The friction between iron and iron causes the greatest damage, and the brake disc will be worn out soon. Do you need to replace the brake disc after it is worn? This is a question that many car owners with worn brake discs will ask. Today we will talk about it in detail.
If the brake disc is slightly worn, it does not need to be replaced. According to the original thickness, wear width and depth of the brake disc, the disc can be repaired as appropriate. However, most of the worn brake discs encountered in practice have been replaced for two reasons. First of all, many brake discs are seriously worn and have no maintenance value. The friction between iron and iron will make a noise. If you don't care about this noise, the brake disc will be completely damaged if you drive for a few days. Even if there is a noise, drive to the 4S store for inspection immediately. If it is far away from the 4S store, the brake disc will be worn out after arriving. If the wear is serious, it must be replaced directly.
Secondly, the original service life of the brake disc is not long, so there is no maintenance value. There is no fixed kilometer for replacing the brake disc. It depends on the wear depth. Generally, it is recommended to replace the brake disc if the wear depth of one side exceeds 2mm. Normally, 3-4 pairs of brake pads are required to wear the brake disc to the limit. If you are the second brake pad or the third brake pad, that is, the remaining life of the brake disc is less than half, and you need to replace it after wear. Because even if the wear is slight and the groove is shallow, the disc needs to be polished to a depth of 0.5 to 1mm. After grinding, the brake disc will reach the thickness to be replaced, so it needs to be replaced directly.
The brake disc is worn. Can you replace it with a new brake pad without repair? No, first of all, the brake disc is worn on a large area. It must be worn unevenly. There are many grooves on it. After the new brake pad is replaced, the brake pad is flat, so the contact area with the brake disc is greatly reduced, the braking force on this side will be greatly reduced, and the brake will deviate, which is very dangerous. Secondly, the brake pad will be worn out and many grooves will be worn out on the surface. Finally, after the brake disc is worn, the thickness may not meet the standard, and the strength will decrease if the thickness is insufficient. There is a risk of fracture of the brake disc during emergency braking. Therefore, the brake disc is worn and must be repaired or replaced.
The price of the brake disc is about several hundred to thousands of yuan. The price of the optical disc needs one or two hundred yuan. The disassembly and assembly also requires labor costs. The optical disc often has some hidden dangers due to equipment and technical problems. For example, if it is not smooth, the high-speed brake will shake, and it needs to be repaired again. Or the brake disc thickness is lower than the minimum value due to more wear and tear, and there are hidden dangers. Therefore, if the brake disc is worn out, as long as it is not particularly slight, it can be replaced. It is not necessary to replace the damaged one at the same time.