What Causes Abnormal Noise When Braking?

[Mia]

There are 6 main reasons for abnormal noise during braking: 1. Poor quality brake pads: Brake pads made of overly hard materials can produce abnormal noises during braking and may also damage the brake discs. It is necessary to replace them with original brake pads at an authorized 4S shop. 2. Foreign objects in the brake disc: When driving on complex road conditions, wheels can easily pick up and throw stones or other foreign objects. Unlike drum brakes, disc brakes can trap these objects between the brake pads and discs, causing noise during braking. These objects should be promptly removed. 3. Severe wear of the brake disc: Friction between the brake pads and an uneven brake disc can also produce abnormal noises. The brake disc should be replaced in time. 4. Severe wear of the brake pads: After prolonged use, brake pads thin out due to continuous friction. Excessively thin brake pads not only reduce braking efficiency but also harden, leading to noise during braking. Replace the brake pads promptly. 5. Rust on the brake disc: Years of exposure to weather can cause the brake disc to rust. Applying the brakes several times can wear off the rust layer. 6. Improper installation: Loose or incorrectly installed components can also cause abnormal noises.

[DeClaire]

I haven't been driving for long, and recently there's been a screeching sound when braking, like the sharp noise of metal rubbing. This worries me a lot because in city traffic, if the brakes fail, it could be dangerous. I've looked into it and found that common causes could be that the brake pads are worn very thin, causing the metal backing to rub directly against the brake disc, creating noise; or that dust, small stones, or rust have built up on the brake disc, especially after rain or if the car has been parked outside for a long time. Newly replaced brake pads sometimes make noise during the break-in period, but this usually goes away after driving for a while. I recommend stopping the car immediately and doing a quick check yourself, but if you're not sure what to do, it's best to take it to a professional repair shop for inspection and replacement. The braking system is a matter of life and death, so don't delay.

[MakaylaLynn]

I've been driving for over a decade and encountered brake squealing several times. Once after rainy days, the brake discs rusted, squeaking whenever I braked until the rust wore off after some driving. Other times, uneven brake pads or grooves on the disc surface caused noise during friction, or small particles like sand got stuck, especially after car washes. Don't forget the wear indicators on brake pads—they emit warning sounds when reached, signaling it's time for new pads. Delaying replacement can damage brake discs, doubling repair costs. I usually check my brake pad thickness monthly and replace them immediately when thin. Regular brake fluid maintenance also prevents issues—safe driving is what truly matters.

[VivianRose]

Brake squealing is quite common in the automotive world, and I believe it's caused by vibration noise from material friction. For example, OEM brake pads with high metal content can produce squeaky sounds due to metal-on-metal contact. Or when the car is first started, the cold-contracted brake discs may briefly make noise. After upgrading to high-performance brake systems, the cooling design might increase noise levels. However, these aren't major concerns—just check if the calipers are stuck or if there are foreign objects. Regular replacement of wear-resistant pads can prevent issues.