Industry News

Why Does the New Brake Pad Make Abnormal Noise?

2022-08-31
The cause of abnormal noise from brake pads
When the brake pad makes abnormal noise after replacement, the first reaction of the owner must be that there is a quality problem with the brake pad. If inferior brake pads are selected, abnormal noise may indeed be caused by the quality problem of friction materials. However, if genuine brake pads are selected, the possibility of quality problems of the products is very small.

Then, what are the other common reasons that cause the brake pad to make abnormal noise soon after replacement, and how to solve it? Let's talk about it in detail.

Why does the brake pad make abnormal noise during the running in period?

Solution:

After the new brake pads are installed, the brake pads shall be properly run in. After running in, the contact surface is complete and the braking efficiency reaches the best.
The correct running in process is shown in the figure above.
Tips for running in period:
After the brake pad is installed, the brake pedal must be stepped several times before starting to ensure that the excessive clearance caused by installation is completely eliminated;
The best braking effect can be achieved only after running in for 200 km; Continuous braking and emergency braking shall be avoided as much as possible during the running in period.


When the brake disc meets water at high temperature, it will cause instant "quenching" to form hard spots on the surface of the brake disc, and the toughness will decrease. During braking, the quenched metal of the brake disc intrudes into the brake pad, resulting in abnormal noise.
Although the foreign matter hard spot will not affect the braking performance, it will cause abnormal consumption of the brake disc and braking noise, so it should be handled in time.
Solution:
Check and clean or replace the brake disc; Grind or replace the brake pad.


The brake caliper does not return to its original position and is worn

Cause:
As the brake caliper piston is stuck and the guide pin lubrication is poor, the contact between the brake pad and the brake disc is incomplete, resulting in abnormal noise, reducing the braking efficiency and shortening the service life of the brake pad.
Solution:
Check the return of brake cylinder and guide pin; Check the translation of the brake pad in the bracket; Conduct in-depth maintenance of the braking system; Replace the brake pads.


Cause:
Due to the excessive use of the brake disc, the step on the edge, the mismatch with the brake pad or the larger friction area than the original factory, the edge wear of the friction material of the brake pad is more serious than that of the middle part, resulting in the abnormal high-frequency noise of the brake, the vibration of the brake pedal and the abnormal wear of the friction material.
Solution:
Check whether the brake pad matches the vehicle type; Check the friction area difference between the original brake pad and the new brake pad.
Check the thickness of the brake disc and replace the brake disc if necessary.

Cause:
In the wet morning of spring and winter, it is easy to produce low-frequency harsh braking noise. The reason is that when the brake disc is in a humid environment, it is easy to form an oxide layer on the surface, resulting in changes in the contact surface between the brake pad and the disc, resulting in abnormal noise.
Solution:
After repeated braking, the oxidized part on the surface of the brake disc is ground flat, and the brake pad and the brake disc are closely fitted during braking, and the abnormal noise is eliminated.

Cause:

Due to the brake overload, there is abnormal sound when stepping on the brake, braking is weak, the brake pad surface is bright, there is glaze and slag.
Solution:
Check the return of brake caliper and brake pad; Check the brake disc and replace it as necessary.


Brake pads are consumables and related to driving safety. Therefore, we should develop a good habit of regular inspection and timely replacement.
Remind you that the brake pads must be inspected or replaced in the following situations.
When the thickness of the brake pad is less than the minimum standard allowed by the manufacturer; When the wear indicator on the brake pad contacts the brake disc; When the instrument panel prompts the brake pad replacement information; When the brake pad is polluted by oil or grease; When the brake pad is abnormally worn or abnormally worn.