Don t be nervous if the brakes make abnormal noises, these situations don t need to be repaired at a

Abnormal brake noise is the result of these situations not to be deceived.

It is believed that the abnormal noise of the car is a problem that many car owners are very concerned about; If there is an abnormal noise when the car brakes, what should we do? Causes and countermeasures of abnormal noise when braking in automobiles.

Generally speaking, there are five reasons for abnormal brake noise in automobiles:

1. The thickness of the automobile brake disc and brake disc changes in the circumferential direction;

2. The automobile brake disc is deformed or improperly assembled;

3. Automobile wheel hub wheel hub is deformed or has surface defects;

4. There is oil on the surface of the wheel hub and the brake disc or between them;

5. There is a problem with the friction material of automobile brake;

Generally speaking, after the automobile brake disc and brake pad brake pad are used to a certain mileage, due to braking, friction produces a lot of heat and debris, and the thermal stress of high temperature will produce deep scratches and surface grooves on the working surface of the brake disc, and it will also cause the brake pad brake pad to be worn to varying degrees, and the brake pad will become very hard with the continuous extension of the use time, and the brake will produce strong resistance by the friction between the brake pad and the brake disc, so as to achieve the effect of braking. The factors of braking force are: compression force (thrust of the brake cylinder), friction coefficient (material related), contact area (the contact surface between the brake pad and the brake disc is determined, in the case of the first two unchanged, the larger the contact surface, the greater the braking force generated, and the better the braking effect. ）

Therefore, if you find that there is a problem with the brakes of the car, you must conduct a detailed inspection of the brake system of the car; to avoid car accidents.

When we brake, the brake pads squeak when they rub against the brake discs, so why does the car squeak when we apply the brakes?

Check and clean up in time. The brake pads may be stained with fine particles and foreign bodies, resulting in abnormal noises during braking, and the gap between the brake calipers and brake pads is too large or too small, which is also easy to cause brake system noise.

On the issue of abnormal noise of automobiles, it is difficult for ordinary car owners to distinguish which ones are abnormal noises and which ones are reasonable abnormal noises. Only nearly 20% of the vehicles that went to the repair shop to detect abnormal noises really had problems. Models equipped with turbocharged engines are different; Models with engine guards may also make noises due to friction; After some car owners come into contact with different cars, it is likely that due to their lack of understanding of mechanical knowledge, they mistake reasonable abnormal noise as a vehicle failure.

Therefore, learn to distinguish the abnormal noise of the car and avoid wasting time and energy.

Second, the identification method of car noise:

In practice, due to the limitations of working conditions, it is difficult to measure the sound of the car with special instruments, and the sound of the car can only be described and compared with the judgment of the sound in daily life. For example, the "rattle" sound caused by the dry friction of the bearing, and the "click" sound similar to the small hammer hitting the cement floor caused by the excessive valve clearance.

1. Correctly distinguish between normal and abnormal sounds.

The vibration of each mechanism in the work of the car will emit a variety of sounds, but the sound does not mean that the car is faulty, in order to avoid unnecessary disassembly, we must first distinguish between normal sound and abnormal noise. The normal vibration sound of each system component (such as the noise on the surface of the engine), the impact sound of the gear when shifting, the air intake sound and exhaust sound of using gas as the working source, and the gear meshing noise are all normal sounds. Abnormal noise (abnormal noise) can be divided into slight noise, general noise and malignant noise according to the impact on the performance of the car.

Slight noise, such as the flashover sound of high-voltage electric leakage, the slight loose sound of rolling bearings, etc., the general volume is small, the degree of wear of the parts is not large, and there is no significant change for a long time, and this kind of fault can still maintain the normal operation of the car without repair.

3. When diagnosing abnormal noise, attention should be paid to creating good auscultation conditions and trying to eliminate the interference of other noises, so as not to affect the accuracy of judgment.

It is best to consciously amplify or reduce the sound, that is, use a screw or other metal rod as a stestological instrument to contact the sound part to amplify the sound, or use a single cylinder fire cut-off to reduce the sound to meet the diagnostic needs. The auscultation site should be kept quiet to minimize human interference.

First of all, if our car is a new car, abnormal noise is a very normal phenomenon, because the brake pads of the car are basically new, and they also need a process of rubbing against each other. The abnormal loudness just means that it will disappear after the run-in, so don't worry.

However, there are other conditions that can cause abnormal braking.

1.There was sand in the brake discs. Under normal circumstances, the new car we just bought will not make abnormal noise when the brakes are applied.

If your car hasn't run many kilometers, the brakes will make unusual noises, mostly because there are particles such as sand or iron powder in the brakes. At this time, as soon as the brakes are pressed, a screeching sound will be made. In this case, we can wash the car with a high-pressure water gun.

If not, we have to open it and clean it up. If you don't care, it will accelerate the wear of the brake pads and may even damage the brake discs.

2.The brake pads are too stiff. Some new cars that have just been bought will make unusual noises when braking, especially when the brakes are lightly pressed.

Generally, the brake pads are made of hard materials, and the abnormal sound disappears when the brakes are applied again. Usually we can ignore this situation and wait for it to run in and look at it later. If you really can't stand the sound, you can change a pair of brake pads to solve the problem.

3.The brake pads are worn to the limit. Because brake pads are consumables, they are thick.

When it comes to quick change, the manufacturer deliberately adds some metal particles when it is closest to the wear limit. When you apply the brakes, the bench will produce an unusual noise that reminds you that you should replace the brake pads. In fact, when you encounter such a situation, you must change it as soon as possible.

Because the braking system is related to driving safety, this cannot be delayed or ignored.

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There are many causes of abnormal brake noise, but not every abnormal noise indicates a problem with the braking system, and some abnormal noises are not a sign of failure. Let's share with you those things related to abnormal brake noise. Normal abnormal noise of the brake 1 When the brake is pressed, there is a "squeak" sound.

If it's a new car or just had the brake pads replaced, it's likely that the brake pads and discs haven't been fully snapped in, so sometimes there is a slight grinding sound. As long as the vehicle is driven for a while, the abnormal noise will disappear. Situation 2: When it starts after a rainy or snowy day, there is a "boom" sound.

This is due to the brake discs and pads sticking together due to corrosion. This kind of abnormal noise is generally applied to the brakes a few times after the vehicle is on the road, and the rust on the brake disc is worn off. Situation 3: The brake system enters the sand and makes a "hissing" sound.

There is no need to panic in this case, as long as you continue to drive, the sand and gravel will fall out on its own, and the abnormal noise will disappear. Situation 4: When braking suddenly, there is a "click" sound, and at the same time, there is a continuous vibration from the brake pedal. When this happens, many people worry that the brake system is causing problems due to sudden braking.

In fact, it is likely that this is caused by the sudden braking triggering the ABS system. When ABS is working, it is equivalent to the vehicle braking at a high frequency, at this time, you will feel a strong vibration of the brake pedal, and at the same time, you will hear the brake master cylinder make a "click" sound, so this situation is also normal. It should be noted that if the abnormal brake noise is found to be continuous, it needs to be repaired in time.

Under normal circumstances, the abnormal brake noise that cannot be solved for a long time is mostly caused by excessive wear and tear of the brake pads after a long time in the car. In this case, it can be solved by replacing the brake pads; If the brake disc is also damaged, it should be replaced. When replacing, pay attention to choosing brake pads or brake discs of the same model, otherwise abnormal noise may still occur after replacement.

Brake Pad Wear Indicator Lights UpWhen the brake pad wear indicator lights up, it means that the brake pads are almost at the wear limit. Therefore, after the brake pad wear indicator light is on, you should drive to the maintenance mechanism as soon as possible to replace the brake pad.

The brakes make abnormal noises, it is normal not to step on the brakes, and there are no other noises in the chassis. Obviously, this must be a problem with the braking system. The result of the master's inspection is that the brake disc is uneven, and the brake pads have reached the wear limit.