Why is there a strange noise when braking at low speed?
3 Answers
Strange noises when braking at low speed are a normal part of ABS activation. The working process of ABS is actually a cyclic process of locking and releasing, keeping the vehicle in a state of intermittent rolling near the lock-up point. Therefore, when you brake hard and trigger the ABS, it will produce a clunking sound, which is normal. In this situation, you should press the brake pedal firmly to the floor. For automatic transmission vehicles, the "clunk" sound when braking is mainly due to the electronic interaction between the braking system and the automatic transmission. The specific reasons are as follows: 1. Excessive wear of brake discs and brake pads: Both brake discs and brake pads are high-wear components. Each time you brake, these two parts rub against each other, leading to natural wear over time. When they are excessively worn, strange noises will occur, so regular inspection and replacement are necessary. Typically, brake pads should be replaced every 60,000 to 80,000 kilometers, while brake discs should be replaced every 100,000 to 120,000 kilometers. 2. Incorrect installation of brake pads: If the brake pads are installed backward or the model does not match, strange noises may also occur. You can have the brake pads reinstalled. When installing brake pads, it is recommended to go to a professional auto repair shop, especially for owners who have had their brake pads replaced at roadside stalls. 3. Other possible causes: Issues with the caliper, brake disc, or brake pads can all produce this noise. If the noise persists, the first thing to check is whether there is any dragging brake. Poor caliper reset can cause prolonged friction between the disc and the pad, which may produce strange noises under certain conditions. Additionally, if there are foreign objects on the brake pads or brake discs, this can also lead to strange noises.
A squeaking noise when braking at low speeds is mostly due to worn-out brake pads. Having driven hundreds of thousands of kilometers, I've encountered this issue many times. When the pads thin out, the warning metal tabs scrape against the brake disc, producing a squeaking or screeching sound. Especially in humid weather, rust on the disc surface can also cause noise when rubbing against the thin layer of rust at low speeds. I've personally experienced severe noise after driving in the rain, but it improved significantly after washing the car and gently applying the brakes a few times. Prevention is key—regularly check the thickness of your brake system; typically, replace the pads around every 50,000 kilometers. Don't wait until the noise persists, as it could damage the more expensive brake discs. Safe driving means not overlooking these small warning signs.
As someone who frequently tinkers with cars, I believe that low-speed brake squealing is often caused by hardened spots on the brake pads or accumulated dust. The vibration during friction generates noise, and it could also be due to rusted caliper sliders, making the pads less flexible and causing squeaks. During inspection, you can remove the wheels to check the pad thickness; normally, it should be above 4mm—replace them if they're too thin. Applying some anti-noise paste at the contact points can alleviate the issue, but make sure you have all the necessary tools before starting, as messing with the brake system can be dangerous. Additionally, new brake pads might produce some break-in noise when first installed, but this usually disappears after a few hundred kilometers. Upgrading to high-quality pads, such as ceramic ones, offers quieter and more durable performance.
