If brake pads have abnormal sound, how should we solve and analyze.

Brake abnormal sound is a very headache problem, there are many reasons for brake abnormal sound, whether it is new or old, it may cause brake abnormal sound, in the end why will produce brake pad abnormal sound? Let's take a look.

When braking, the brake pump applies a force F to the brake disc through the brake pad, and makes the rotating brake disc from motion to static, at this time there is a relative speed V between the brake disc and the brake pad. FxV= vibration frequency, the sound is caused by vibration. There is a critical value concept involved here, that is, when the vibration frequency is higher than the critical value, we will hear the abnormal sound produced by the brake.

Vibrations that do not reach this threshold produce sounds that we cannot hear. This is the abnormal sound of brake pads. Let's analyze the reasons for the abnormal sound of brake pads.

Cause Analysis Of Abnormal Sound Of Brake Pad

1. Abnormal Sound Caused By Insufficient Contact Surface

(When the contact surface is not enough, the pressure per unit area of brake pad will increase.) Because there is no disc causing the brake pads to ring.

As shown in Figure B, without polishing the old disc before installing the new film, the new film will only rub against the chamfering of the old disc. Ninety percent of noise is caused by this.

Finally used brake pads will appear as shown in Figure C, that is, arc-shaped wear at both ends.

B) There are defects in the brake system, so that the brake pad can only partially contact with the disc, causing abnormal brake pad sound.

The brake pad shown in Figure D is only partially in contact with the brake disc, which will increase the pressure per unit area of the brake and produce abnormal sound. It is recommended to check the calipers, guide pins, sub-pumps and other parts of the brake. Is there a foreign body block brake pad normal sliding, so that the contact area is reduced, resulting in abnormal sound.

C) Artificial factors of private grinding and reconstruction of the brake pad, so that the contact area between the brake pad and the disc is reduced, so that the brake pad abnormal sound.

Figure E shows the polished and reformed brake pads. After processing, the friction surface area of brake pads decreases, and the contact surface between brake pads and disc decreases. Increase the pressure of brake pad per unit area, producing abnormal sound. And affect the braking effect of the brake.

2. Abnormal Sound Caused By High Braking Temperature

Brake pad periphery is white words that brake pad friction material properties have been partially changed. Abnormally frequent emergency braking, wheel locking, and caliper failure can cause braking to overheat for long periods. The fault will reduce the braking efficiency of brake pads and embrittlement the friction material of brake pads and even cause rupture.

Lead to abnormal sound, and seriously affect the service life of brake pads.

Summary Of Reasons For Abnormal Sound Of Brake Pads

1. The new car running-in, brake pad running-in is a very important link, usually run hundreds of kilometers, to feel the brake will be more comfortable;

2. The new brake pad also need to run in order to better combine with the old disc, just put on, will feel the brake is very hard, usually also need to drive hundreds of kilometers to feel better;

3. The vehicle driving, there may be a very small sand into the middle of the piece and plate, sometimes due to friction abnormal sound, this kind of situation does not need to repair, run to make small sand fell out;

4. With no running in good and sound, has the owner simply run slammed on the brake, so that we can in a short period of time in the brakes, but it will make the brake pads wear more severe, that is, equal to reduce the service life of the brake pads, therefore, suggest you go to run for a period of time to watch, don't go to artificially forcing wear pads;

5. The brake disc fixed screw loss or damage, will also cause abnormal brake sound;

6. The brake system failure, which needs to be checked and repaired.

Brake Pad Abnormal Sound Solution

There are many reasons for the abnormal sound of brake pads, such as:

A- Brake pads are hard.

B- Brake pad wear has left the retaining frame.

C- Excessive brake disc or brake wear.

D- Rust on brake sub-pump.

E- It doesn't work.

F- Slow return position of main kill pump.

Therefore, the processing methods are different. The possible situations and processing methods are as follows:

Brake Pads Screeched Strangely

If it is brake pad abnormal sound is screaming, the first thing to check is despise brake pad is running out (alarm sheet sound). If it is a new film, it is necessary to check that there is no foreign matter between the brake disc and the disc.

When the brake disc wear abnormal, this is due to the brake disc surface dirty, brake disc material density is not uniform, high working temperature, brake disc installation torque does not match.

Check: check the brake disc before replacing the brake disc; Check brake disc thickness with caliper; Reinstall fixed brake disc bolts; Measure the flatness of brake disc working surface.

The high frequency sounds sharp, and when the disc and disc vibrate at the same frequency, they resonate to produce a squeal.

Check caliper: guide rail is smooth, piston oil seal is not damaged; All anti-noise clamp and brake sheet are suitable, installation is correct; Whether the brake is too smooth, whether is overused.

Brakes Make a Muffled Sound

If it is muffled, more brake caliper problems, such as movable pin wear, spring off, etc.

Caliper noise, caused by caliper assembly vibration, may also be due to suspension vibration. New car calipers or suspension systems with slight vibration, early morning sensitivity, such as winter morning, is particularly common. Check calipers, suspension system and bushings.

Brakes Squeaked

If it is silk, then the problem is more, calipers, brake discs, brake pads may have problems. If the sound is continuous, first check there is no drag brake, caliper reset will lead to disc and disc friction for a long time, under certain conditions will give out abnormal sound. Check whether there is any foreign matter stuck between the disc and the disc. If it is a new film, it depends on the brake disc grooves, because local friction will lead to abnormal sound. If there is no problem with the disc, it is necessary to consider whether the brake pad is too hard, or the silencer is installed incorrectly.

To sum up, the brake is callipers, brake pads and brake discs, which are all likely to produce abnormal sound. But people tend to blame the problem on the brake pad, which is wrong, after reading this article should be on the brake abnormal sound of the fault cause and how to solve the problem have some clue.