According to a car repair technician at Ninety Eight Auto (Cat Lai ward, Ho Chi Minh City), one of the common causes when car brake pads make unusual noises is the use of poor quality brake pads.
Standard brake pads may have unstable friction characteristics, making the contact between the brake pads and the brake disc uneven. In the long run, this condition can cause the brake disc surface to wear unevenly, and also affect braking efficiency.
When the surface of contact between the brake pad and the brake disc is unstable, the driver may hear a whistle or a "kike" sound when braking. If the brake disc has been worn or deformed, continuing to use a new brake pad may also make the braking system noise.
Another case may occur after refining the brake disc surface. The convenience or processing of the brake disc surface needs to ensure flatness and reversal within the manufacturer's technical limits. If the refined surface does not meet the requirements, the brake pad may be in uneven contact with the brake disc. In this case, friction may generate vibration and noise when braking.
Some repair facilities can process or change the shape of the brake pads to install on systems that do not use the correct type of spare parts designed for the car. Although it can be used for a period of time, this option poses risks because the friction material, size, thickness and heat resistance of the brake pads may not be suitable for the original brake system.
Therefore, when changing brake pads, car owners should use the correct type of spare parts, suitable for the technical specifications of the car. If the brake disc shows signs of uneven wear or the surface is damaged, it is necessary to check and handle it according to technical limits instead of arbitrarily processing or repairing.
