Why is there abnormal noise when braking at low speed?

[DeRosalie]

Abnormal noise during low-speed braking can occur due to the following reasons: 1. Excessive wear of brake discs and brake pads. Both components are high-wear items that experience friction with each braking action. Over time, natural wear occurs, and when excessive, abnormal noises may arise. Therefore, regular inspection and replacement are necessary. 2. Improper installation of brake pads. If brake pads are installed incorrectly or the model does not match, abnormal noises may occur. Reinstalling the brake pads is required. When installing brake pads, it is advisable to visit a professional auto repair shop, especially for owners who have had their brake pads replaced at non-standard shops. 3. Generally, faults in components like calipers, brake discs, or brake pads can cause such noises. If the noise is continuous, first check for dragging brakes. Poor caliper resetting can lead to prolonged friction between the disc and pad, producing abnormal noises under certain conditions. Additionally, foreign objects on the brake pads or discs may also cause abnormal noises.

[LeBeau]

I've been driving for almost twenty years, and it's quite common to hear strange noises when braking at low speeds, especially in the early morning or after rain. The main reason is rust or dust buildup on the brake discs. When you start driving, the brake pads rubbing against the rust can cause a squeaking sound, which is really annoying. Another possibility is that the brake pads have worn down to the metal backing plate, producing a sharp noise—that's when safety becomes a concern. I've experienced this before. When I took it to the repair shop, the mechanic said it was time to replace the brake pads, and it only cost a little over 300 yuan to fix. Regular inspections are crucial. I recommend checking the condition of the discs and pads every 20,000 kilometers. Otherwise, if the braking force is insufficient at high speeds, that’s really scary. You can also clean the discs and pads simply when washing your car—just keep them dry.

[NathanMarie]

I enjoy tinkering with cars myself, and squeaky brakes at low speeds are usually a sign of minor issues in your braking system. I suspect it might be due to mud or rust on the brake discs, which makes the squeaking more noticeable when driving slowly in the city. You can start by checking the thickness of the brake pads—use a flashlight to look for the wear indicators inside the wheel hub. If only 1-2mm remains, it’s time to replace them, or else the friction could damage the discs. Also, don’t overlook loose brake calipers; try tightening the screws. I once fixed a squeak this way—just spent 50 bucks on new pads and installed them. Remember to wear gloves for safety. If ignored long-term, the noise will worsen, affecting driving and even increasing fuel consumption!

[MacCalvin]

As a fan with some mechanical knowledge, I believe that low-speed brake squealing is usually caused by physical friction issues. For example, uneven brake disc surfaces or metal oxidation due to air humidity can generate friction sounds. Some new cars may have slight noises during the break-in period, but persistent noise should raise concerns, possibly indicating material aging. I recommend getting a professional equipment check-up and choosing dry parking spots to reduce corrosion. This issue is more prominent in older vehicles, and replacing the system with a new one can restore quiet operation.