Why Does the Car Brake Squeak?
2 Answers
The reasons for car brake squeaking: 1. When the vehicle is stationary, a slight squeaking sound occurs upon gently pressing the brake pedal, which is due to the return spring of the brake light switch on the pedal. 2. When the vehicle is moving at low speed and the brake is applied, a noticeable squeaking sound may come from the brake disc area. For new cars or after replacing brake pads, repeated high-pitched squealing noises often occur because the brake disc surface becomes mirror-smooth after use. At this point, friction between the brake pad surface and the mirror-smooth brake disc creates a hardened layer. The friction between this hardened layer and the mirror-smooth brake disc easily produces squealing sounds. If only the brake pads are simply polished to remove the hardened layer, the squeaking may stop temporarily, but since the brake disc remains smooth, the hardened layer will quickly reform on the brake pad surface, causing the noise to persist.
I've handled many similar cases before. The squeaking sound from car brakes is mostly due to excessive wear on the brake pads. When they wear down to a certain point, they produce a harsh noise, like metal scraping. It could also be caused by dust, small stones, or oil contamination on the brake discs, leading to uneven friction. If you don't replace the pads promptly, braking performance will deteriorate, and you might even damage the brake discs, which would be more expensive and dangerous to repair. I recommend checking the brake pad thickness every month—replace them if they're below 2 mm. The noise tends to be more noticeable in humid weather, but if it's temporary, it's not a major issue. In short, don't ignore the noise; visit a repair shop as soon as possible to ensure driving safety.
