What Causes the Abnormal Noise When Braking in a New Car?
3 Answers
The reasons for abnormal noise when braking in a new car are: 1. The brake pads are in the break-in period. New brake pads and brake discs require a break-in process, and this abnormal noise is normal during this time; 2. Metal particles appear in the brake pads. The original factory brake pads that come with the car are semi-metallic, and when worn to a certain extent, unevenly distributed high-hardness metal particles may appear. These metal particles spread across the brake pads and create noise when in contact with the brake disc; 3. Excessive wear of the brake disc and brake pads. When excessively worn, abnormal noise may occur, so regular inspection and replacement are necessary. The replacement cycle for brake pads is 60,000 to 80,000 kilometers, and for brake discs, it is 100,000 to 120,000 kilometers; 4. Deformation of the brake disc. If the car produces abnormal noise and vibration when braking, it may be due to a deformed brake disc, which requires replacement.
I experienced a squeaking noise when pressing the brake pedal shortly after buying my new car, which was quite annoying. After researching and consulting friends, I found that brake noise in new cars is quite common, mainly because the brake pads and discs need to adapt to each other's surfaces during the break-in period. The rough surfaces of new components can easily produce noise when rubbing, similar to how new tires make some noise when first used. Another possible cause is small dust particles or tiny stones getting stuck in the brake pads, especially after driving on dusty roads. From my own experience, the noise usually fades away after driving a few hundred kilometers. If it doesn’t disappear or gets worse—such as being accompanied by vibrations or unusual smells—it’s best to visit the dealership for a check-up immediately. After all, new cars come with a warranty, and delaying could make the problem worse. Driving safety comes first, and ignoring brake noise might affect stopping distance.
As someone who frequently studies automotive mechanical knowledge, I think there are quite a few reasons for brake noise in new cars. The most likely cause is that newly installed brake components need some time to wear in and become smooth. For example, the metal materials of brake pads and discs can produce noise during initial friction, and temperature changes can amplify the sound, especially in humid weather. Additionally, incomplete assembly during installation or tiny debris trapped in the gaps can also trigger abnormal noises. I've personally observed that the noise tends to lessen after the first few hundred kilometers of driving. However, if it doesn't disappear, it might indicate a fault in the braking system, such as loose calipers. I recommend doing a simple check for scratches on the brake discs and visiting a professional shop for a tool-based inspection if necessary. Since brakes are crucial for driving safety, avoid modifying parts casually to prevent worsening the noise.
