What Causes Brake Noise During Cold Start?
2 Answers
Reasons for brake noise during cold start: 1. The mechanic installed the brake pads incorrectly. Upon removal, you may notice friction marks only on certain parts of the brake pad surface. In this case, it is necessary to visit a 4S shop to remove and reinstall them properly. 2. Sudden noise after driving for a while is mostly caused by hard objects such as sand, gravel, or metal debris getting stuck in the brake pads when braking. This situation can be resolved by visiting a 4S shop for cleaning. 3. Issues with the brake pads themselves, such as inconsistent friction block dimensions of the same model. The width deviation of friction blocks can reach up to three millimeters, causing the brake disc surface to appear smooth but actually uneven, leading to brake noise.
I have plenty of experience with squeaky brakes during cold starts. Last winter, my car had the same issue, so I specifically consulted an experienced mechanic at the repair shop. He said it's mostly due to the material of the brake pads, especially those with high metal content. In low temperatures, condensation forms a rust film on the surface, causing a screeching sound when the pads and rotors first rub against each other. This is even more noticeable after rain, which pretty much confirms the issue. Another possibility is that newly replaced brake pads haven't been properly bedded in, and the edges aren't perfectly aligned with the brake rotors. However, as long as the noise disappears after a few minutes of driving when temperatures rise, it's generally not a concern. If the squeaking persists after driving several kilometers, then you should check whether the calipers are retracting properly or if there are grooves on the brake rotors.
