What causes abnormal noise in car brake discs?
3 Answers
The reasons for abnormal noise in car brake discs are: 1. Deformation of the brake disc; 2. Severe wear of the brake disc; 3. Foreign objects between the brake pads and the brake disc; 4. Missing or damaged fixing screws of the brake disc; 5. Presence of rust on the car brake disc. The brake disc functions by being clamped to slow down or stop the vehicle when the brake is applied. Brake discs offer effective braking performance and are easier to maintain compared to drum brakes. Drum brakes are sealed and shaped like a drum, rotating while the vehicle is in motion. Inside the drum brake, there are two fixed arc-shaped or semi-circular brake shoes. When the brake is applied, the two brake shoes expand outward under the action of the wheel cylinder, pressing against the inner wall of the brake drum to slow down or stop the vehicle.
I also encountered squeaky brake discs last time. When I took it for inspection, it turned out the brake pads were nearly worn out. The mechanic said the brake pad wear indicator touching the disc would produce metallic friction noise as a safety warning. Additionally, the unusual noise after driving in rain is usually caused by surface rust on brake discs, which can be eliminated by braking several times to wear it off. If the noise is a regular clicking sound, it might be small stones stuck between the brake disc gaps. The most troublesome issue is warped or grooved brake discs - my relative's car had severe steering wheel vibration during emergency braking, and it cost 500 yuan to resurface the discs. My advice is don't push your luck, timely inspection can save you the cost of replacing the entire brake disc set.
There are five common causes of brake noise. First is excessive wear of brake pads causing the alarm shim to make friction sounds, requiring immediate replacement. Second is grooves or wavy wear on the brake disc surface, leading to uneven friction. Third is rust on brake discs caused by low temperatures or humid environments, producing scraping sounds while driving. Fourth is hard brake pad material, especially common metal friction sounds during the break-in period after new brake pad installation. Fifth is failed lubrication of brake caliper guide pins, preventing the brake pads from fully retracting. I recommend first visiting a repair shop to check the brake pad thickness and have the mechanic measure the brake disc flatness.