What Causes the High-Pitched Squealing Sound When Braking?
3 Answers
The reasons for high-pitched squealing sounds when braking: 1. The wear indicator emits a sharp noise as a replacement reminder: Most vehicle braking systems are equipped with a warning mechanism to alert drivers to replace brake pads. When the brake pads wear beyond the designated warning threshold, the wear indicator produces a piercing noise to prompt the owner to inspect or replace the brake pads at a service center. Failure to replace them promptly may result in the metal wear indicator scoring fatal grooves into the brake disc, rendering it unusable. Additionally, excessively worn brake pads can lead to brake failure, potentially causing severe accidents. 2. Severely worn brake discs causing noise: If the brake disc is heavily worn, the outer edge beyond the contact area with the brake pad may develop a raised ridge relative to the friction surface. When the corner of the brake pad rubs against this raised edge of the brake disc, it can generate noise. There are generally two solutions: either have the edges of the brake pads ground down at a service center to avoid contact with the raised disc edge, or opt for a complete brake disc replacement. 3. High-pitched squealing during braking in new vehicles: Many owners assume this indicates a manufacturing defect when they hear sharp noises during braking in new cars. However, this is often part of the break-in process between new brake pads and discs. The noise occurs when braking happens to contact a hard spot in the brake pad material. Applying lubricant at a service center can help reduce this noise.
Every time I hear that screeching sound of brakes while driving, it reminds me of my experience when I first learned to drive twenty years ago. Now, my experience tells me that the most common cause is the brake pads wearing too thin, exposing the metal parts that scrape against the brake disc, producing a sharp noise, especially on wet and slippery roads during rainy days. Another possibility is the accumulation of dust or small stones stuck in the brakes, causing uneven friction. I’ve made it a habit to regularly check the thickness of the brake pads and replace them as soon as they wear thin. Otherwise, as the noise grows louder and the braking distance increases, it could lead to accidents, especially on highways. I recommend checking first if there’s dust buildup in the brake system or visiting a repair shop to measure the wear level. Early intervention can save a lot on repair costs and ensure safe driving.
As a new driver, I encountered this issue last month. Just after starting the car, I heard a squeaking noise from the chassis, which made me panic, fearing the brakes might suddenly fail. Later, I asked some friends, and they said the main reason was that the brake pads were nearly worn out, causing metal to scrape against the brake disc. Additionally, if it's a new car or the brake pads were recently replaced, it could be due to poor-quality shims or improper installation, and the noise is more likely to occur when the air humidity is high. I was so scared that I immediately drove the car to the repair shop for an inspection. After spending some money to replace the parts, the problem was fixed. It's important to develop a habit of regularly maintaining the brake system while driving; otherwise, small issues can turn into big problems, and the combined cost of repairs and risks isn't worth it. Safety first—never delay addressing such issues.
