New brake pads, need to pay attention to these three points

when replacing the brake pads, we must pay attention to the edges and corners of the grinding.

The general brake pad factory reserved a inclined section, commonly known as "chamfer".In addition to this' chamfering ', the entire edge position of the friction surface needs to be sanded, this process is actually noise matching.Because the old brake pad and brake disc after tens of thousands of kilometers of "lingering", each other formed a certain modeling of the complementary.

In other words, the old brake pads have carved a groove of their own in the brake disc.Although the naked eye is not easy to distinguish, but after the brake pad replaced, there will be a certain friction noise.Because they don't match, it's like wearing shoes that are a size too small.So, by grinding the edges and corners so that the new brake pads are fully lodged in the grooves of the left brake disc, there is no noise and there is enough braking force.

So the question is, will the grooves on the brake disc be rubbed out deeper and deeper?Of course. Generally speaking, when the depth exceeds 2mm, the brake disc should be replaced.

after changing the brake pad, try not to brake, not to brake sharply.Because the friction surface of the new brake pad, and the surface of the brake disc is not completely fit.

How much area this fits directly determines the effect of the brake.Because the old brake pad left its own traces on the brake disc, it is uneven to see with a microscope, so the new brake pad replaced, to adapt to these traces, slowly contact area will become larger.There is a physics problem, here also to tell you about.Many people believe that the larger the size of the brake pad, that is, the greater the total area of friction, the greater the braking force.This statement, according to high school physics interpretation, is wrong.Because according to F= UN, friction doesn't depend on the area of contact.

So, why do high-performance models use large size brake disc and brake pads?The more reasonable explanation is that the increase of contact area is conducive to heat dissipation and reduces the thermal attenuation effect during braking.

The so-called thermal attenuation, refers to the braking force, due to the intense friction between the brake pad and the brake disc heat generation, resulting in the brake pad friction material thermal expansion soft, friction coefficient reduction, thus affecting the braking performance.

So, it should be said that the bigger the brake pad, the better the braking effect, but not necessarily more friction.

Of course, friction itself is a very complicated subject.Strictly speaking, friction is related to contact area, but from a macroscopic point of view, the effect of contact area is ignored.

after replacing the new brake pad, we must pay attention to the running-in, so that the brake pad and the brake disc as soon as possible to achieve a better fit, in order to ensure the braking effect.

Generally speaking, after the new brake pad, it is necessary to go through at least 500km of full run-in to make the new brake pad into the best working state.

Before this, the speed should be properly controlled, on the high speed should do a good job of road conditions in advance, in case of sudden braking, affect the braking force.

In rain and snow weather, we should pay more attention to grasp the brake lift, keep the car distance.

After replacing the new brake pad, there is a slight abnormal sound in the braking process is a normal phenomenon. If it disappears after running in, then there is no need to care.

However, if the noise is obvious and lasts for a long time, you need to check with a quick repair shop to see if the edges are fraying and causing the noise.

In general, if the brake pads are replaced more than 3 times, a new brake disc is needed.Of course, in the process of using the car, every time you replace the brake pad, you should check the wear depth of the brake disc.If it reaches 2mm, it should be replaced in time.

How do you detect this depth?Use caliper to measure the height of the edge position of the lower brake disc.Because the edge position is not in contact with the brake pads, there is no friction.

If the bulge at the edge reaches a height of 2mm, the brake disc should be replaced.

when replacing the new brake pad, you can ask the teacher to help check whether the return position of the brake sub-pump is good.

If for some reason, the return of the brake pump, that is, the hydraulic piston, is not normal, it will seriously wear the brake pad and brake disc.That would be a big loss.