What Causes the Squeaking Sound in BMW 3 Series Brakes?
2 Answers
The reasons for brake squeaking in BMW 3 Series are as follows: 1. Use of inferior or overly hard brake pads: If inferior or overly hard brake pads are used, they will produce a squeaking sound when rubbing against the brake discs during braking. Therefore, it is essential to use high-quality brake pads when replacing them. 2. Presence of sand or foreign objects between the brake pads and discs: During normal driving, it is inevitable to encounter complex road conditions. Due to the unique design of disc brakes, some sand or foreign objects may get between the brake pads and discs, causing abnormal noises during braking. 3. Severe wear of brake discs: For new cars, a slight squeaking sound during braking is normal and should diminish with more driving. For older vehicles, the noise might be due to rust on the brake discs or pads, which can be resolved by removing them and sanding off the rust layer. If the brake pads are severely worn, they should be replaced. 4. Brake pad warning: There is no strict mileage requirement for replacing brake pads; they should be replaced once they become thin. Some brake pads come with electronic warnings, while lower-end vehicles use warning clips. When the wear reaches the warning line, a squeaking sound will occur, indicating the need for immediate replacement. 5. Incorrect installation of brake pads: If the brake pads are installed incorrectly or do not match the model, abnormal noises may occur. In such cases, the brake pads should be reinstalled. It is advisable to have brake pads installed at professional auto repair shops, especially for owners who have had them replaced at roadside stalls, as extra caution is needed.
To be honest, friends who drive BMW 3 Series often ask me about the squeaky brake issue. This situation is most likely caused by brake pads. The OEM brake pads are made of harder materials, which are wear-resistant but prone to producing sharp noises when cold or at low speeds. Also, if the brake disc surface is scratched by hard objects like small stones, or if the disc surface is uneven with grooves, the metal scraping sound between the pads and disc can be quite annoying. Newly replaced pads will have a break-in period, and the noise will naturally disappear after driving 200-300 kilometers. However, if you feel steering wheel vibration during braking, you should immediately check for brake disc warping—this is no small matter.
