Then, to what extent should the brake pads be replaced? Generally, the remaining two or three millimeters should be replaced, and the thickness should be estimated by yourself. If you don't know how thick two or three millimeters are, you can also compare it with the height of the alarm piece. If the alarm piece is about to be worn, it means that it should be replaced. If the alarm piece has been worn, it need not be tangled and can be replaced directly.

To check the thickness of the brake pad, it is better to remove the tire, so that the remaining thickness can be seen at a glance and it is very accurate. In fact, most of the maintenance personnel are unwilling to remove the tire. They use a flashlight to look from the outside and check the outer brake pads. They also put their hands under the car and touch the inner brake pads. Generally speaking, experienced maintenance personnel can judge accurately. Even if the tire is not removed, the thickness judged by them is almost the same as the actual thickness. If you are inexperienced, you will often make mistakes in judgment. The actual thickness is still very thick, and your own judgment is very thin. You will recommend the car owner to replace it. At this time, you will ask the car owner to replace it because it is very thick. Of course, this is not to cheat the car owner, but the maintenance worker's judgment is wrong. After removing it, I found that it was still very thick. The owner has promised to replace it. As long as the owner doesn't say anything, he won't install the old one again and continue to replace it with a new one. In this way, the car owner actually spent a lot of money and didn't need to replace it.

The brake discs of some cars with a large mileage are worn deeply. If the inner brake pads are inspected by hand, some maintenance workers often make mistakes in judgment. The brake disc is deeply worn, but only the part covered by the brake pad is deeply worn, and the brake pad cannot cover the whole brake disc. Therefore, the outermost circle of the brake disc is not worn, and it is still the original thickness. In this way, some of the brake pads will enter the brake disc. If the brake disc is worn 2 mm deep, the brake pad is still 4 mm deep. From the appearance, the brake pad is only 2 mm deep. Because there are still 2 mm in the brake disc, it will be mistaken that the brake pad should be replaced.

Check the thickness of the brake pads by yourself. If the thickness is very thick, you can see it from the outside. There is no need to remove the tire. If the thickness is relatively thin, the line of sight is oblique from the outside, so it is not easy to grasp the thickness accurately, and the inner part can not be seen, so it is best to remove the tire for inspection. Check the thickness of the brake pads. Both pads should be checked. Many cars have different wear of the two pads, one thick and the other thin. If only one brake pad is inspected and only the thick one is inspected, there is a risk that the brake pad will be worn out if you continue to use the vehicle.