For most Lang Yi owners, the problem of abnormal brake noise should be all too familiar. Whenever it is cloudy and rainy or after washing the car, the brakes always make a shrill sound when the car starts, and the brake disc of my 11 old model Lang Yi inevitably makes a strange noise. It’s just that every time I slammed on the brakes every time I made a noise, the abnormal noise would be reduced a lot, and there would be no abnormal noise in sunny weather. But recently, my old Lang Yi car has abnormal brakes no matter when it is rainy, snowy or sunny, and slamming on the brakes can not eliminate the abnormal noise. After several days of careful observation, I found that the abnormal sound mainly came from the left rear wheel, so when I was not busy on Sunday, I drove the car to the 4s store and asked the repairman to check it.
Came to the 4s store to have a simple communication with the repair master, the answer given by the master may be that the brake pads and the brake disc can not be in normal contact, so there will be abnormal noise, so first lift the vehicle, remove the brake disc, and take a look at the specific situation.
The repairman was so skilful and skilled that he quickly removed the tire.
Start disassembling the brake discs and brake pads.
Take a look at the brake pads that have been removed. This is the brake pads that have been in use for 8 years. See if the thickness can continue to be used.
As I usually have a relatively peaceful driving habit, there is no rapid acceleration and slam on the brakes, so the overall wear of the brake disc is not very serious.
To be honest, this is the first time I have seen the internal structure.
Take a look at whether the brake disc is very smooth.
The brake disc looks very smooth, but in fact, there has been a relatively obvious bulge in the innermost and outermost position, which is caused by the difference in the angle between the brake pad and the brake disc. Due to the fact that the outermost and innermost parts of the brake disc cannot touch the brake pads for a long time, they gradually become uneven.
The reason for the obvious bulge of the brake disc is that the edge position of the brake pad is not smooth.
According to the routine operation of the 4s store, the best solution at this time is to replace the brake pads, but considering that my original brake pads can continue to be used, the maintenance master came up with a solution, that is, to polish the brake pads.
I don’t know the name of this polishing tool, but I just heard from the repairman that this tool is generally used by sheet metal workers to polish.
Take a look at the effect that the repairman has polished for nearly 20 minutes. The four corners of the brake pads are polished very smoothly.
After polishing, the repairman began to reload the brakes and pads.
The brake pads are installed in the calipers.
This picture looks obvious, with two obvious protrusions on the innermost and outermost sides of the brake disc.
After the brake disc and brake pads are loaded, the tires are finally installed.
The whole maintenance process is quite time-consuming, about an hour before and after. After the installation of Wechat was completed, he specially drove to the road and ran for several kilometers. The abnormal sound of the brake disc has been significantly improved, but there is an occasional noise. The opinion given by the maintenance master is that this time the brake disc polishing only reduces the friction between the brake disc and the protruding part. in order to solve the problem completely, you need to find a lathe worker to thoroughly polish the two circles on the inner diameter and outer diameter of the brake disc. After the brake disc is completely polished and leveled, the abnormal noise should disappear completely. The master’s suggestion is very pertinent, another day to find a special machine tool master to solve this protruding problem, at that time can completely solve the abnormal noise.
DaphneAgnes 
2 
September 22, 2024 
