How to identify the brake pads and brake discs need to replace ?

Brake pad is an important part of brake system. The main working principle of the brake is to use the brake pad and brake disc and tires and the ground friction, a huge friction to stop the car, after constant friction brake pad will wear thinner and thinner.

How often are the brake pads changed?

Theoretically speaking, the service life of the front brake pad is 20-40,000km, while the service life of the rear brake pad is 60-100,000km. But different drivers have different driving habits, so it depends on how worn the brake pads are.

I suggest that, on average, the front brake pads should be checked every 30,000 km and the rear brake pads should be checked every 60,000 km to decide whether to replace the brake pads according to the professional scientific test results.

Everyone knows that the brake pads must be replaced when they are worn out, but if they are not found in time to continue using the car, they will wear out the brake disc as well. The brake pads are fixed to an iron plate which, when worn out, will rub against the brake disc when applied again. The friction between iron and iron is the biggest damage, the brake disc will be worn out soon, then whether the brake disc must be replaced after being worn out? This is a question that many car owners who wear out their brake discs will ask.

There is no need to replace the brake disc if it is lightly worn. The disc can be repaired on optical disc according to the original thickness, width and depth of wear. But in practice most of the worn brake discs encountered were replaced, for two reasons. The first is that many of the brake discs are badly worn and have no maintenance value. The friction between iron and iron will produce a sound, if you do not care about this sound a few more days, it is certain that the brake disc will be completely damaged. Even if there is a sound immediately drove to the 4S shop for inspection, if it is far away from the 4S shop, after arriving, the brake disc will be worn out, wear more serious must be directly replaced.

Secondly, the original life of the brake disc is not long, there is no maintenance value. There is no fixed mileage for the replacement of the brake disc, which depends on its wear depth. Generally, it is recommended to replace the single-side wear depth if it exceeds 2mm. In normal use, 3-4 pairs of brake pads are needed to wear the brake disc to its limit. If you have a second brake pad or a third brake pad that has less than half of its remaining life, replace it when it wears out. Because even if the wear is very slight, groove is shallow, want to smooth the disc, also need to wear off 0.5 to 1 mm depth, wear off the brake disc will be the thickness of the replacement, so also want to replace directly.

The brake disc is worn down. Is it possible to replace it with a new brake pad and continue using it without repair? Is not ok, first of all the brake disc large area of wear, must be worn uneven, there are many grooves above. When a new brake pad is put on, 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 run off-track, which is very dangerous. Secondly, the brake pads will be worn out, the surface will also be worn out a lot of grooves. Finally, after the brake disc is worn, the thickness may not meet the standard, the strength of the insufficient thickness will also decrease, and there is a risk of the brake disc breaking during emergency braking. So the brake pads are worn and must be repaired or replaced.