What Causes Squeaky Brakes in Cars?
2 Answers
The main reasons for abnormal brake noises in cars are as follows: 1. Presence of foreign objects like sand between the brake pads and brake discs: Foreign objects can increase friction on the brake pads, leading to abnormal noises during braking, and should be promptly removed. 2. Material issues with the brake pads: Most brake pads are made of a semi-metallic and semi-asbestos material. If the metal in the brake pads is too hard, it can cause abnormal noises during braking. 3. Uneven brake discs: Brake discs may develop uneven surfaces or raised edges due to wear during use. 4. Wear of the brake pad warning device metal piece: High-end cars use warning wires, while low-end cars use physical metal pieces. When the brake pads wear down, the metal piece will directly rub against the brake disc, producing a sharp squeaking sound, which is a normal warning signal.
I've been driving for over a decade, and brake noise is indeed quite common. The most frequent cause is worn brake pads. When the thickness falls below the safety line, the built-in metal shim rubs against the brake disc, producing a sharp sound, like two metal pieces scraping against each other. Another common scenario is rust on the brake discs after rain or car washing, which causes clunking noises when you first start driving but usually disappears after a few hundred meters. Additionally, new brake pads require a break-in period, so some noise during the first 200-300 kilometers is normal. However, if the noise persists for a whole week, it might indicate a trapped stone or a warped brake disc, which needs immediate attention. I remember last time my car had this issue, and upon inspection, we found a small screw stuck in the wheel hub.
