The reasons for the persistent high-pitched buzzing sound in a Mercedes-Benz car are as follows: 1. The wear indicator emits a sharp abnormal noise to prompt replacement: When the brake pads wear beyond the specified warning value, the wear indicator will emit a piercing noise to remind the owner to promptly inspect or replace new brake pads at a repair shop. If not replaced in time, the metal wear indicator will carve a fatal groove on the brake disc, rendering it unusable. Additionally, brake pads worn to the limit may cause brake failure, leading to serious traffic accidents. 2. Severe brake disc wear causing abnormal noise: If the brake disc is severely worn, the outer edge where the brake disc and brake pads do not make contact will become a raised ridge relative to the friction surface. If the corners of the brake pads rub against this raised edge of the brake disc, abnormal noise may occur. There are generally two solutions to this issue: one is to visit a repair shop to grind the edges of the brake pads to avoid contact with the raised edge of the brake disc and prevent friction; the other is to directly replace the brake disc. 3. Sharp, piercing noise when braking: Many owners of new cars believe that a sharp, piercing noise when braking must indicate a quality issue with the vehicle. New brake pads and brake discs require a break-in period. When braking, if the pads happen to rub against a hard spot on the brake pads, this noise can occur. Applying some lubricant at a repair shop can help reduce the noise.
