What Causes Severe Brake Noise When Reversing a Cold Car?
2 Answers
Reasons for severe brake noise when reversing a cold car: There may be foreign objects between the brake pads and brake discs, or the brake pads themselves may be worn. You can check whether the rubber bushings of the chassis components have aged. When braking, the brake pads and brake discs wear in one direction for a long time, causing some metal burrs to appear on one side of the brake pads. When you step on the brake while reversing, the tips of these burrs come into contact with the brake disc, which is the main cause of the noise. Brake pads are critical safety components in a car's braking system, and the effectiveness of all braking depends on them. The heat insulation layer is made of non-heat-conducting materials to insulate heat. The friction block consists of friction materials and adhesives, which are pressed against the brake disc or drum during braking to create friction, thereby achieving the purpose of slowing down or stopping the vehicle.
I've driven many cars before, and brake noise when reversing a cold car is particularly common, especially after parking overnight in humid weather when the brake discs rust. The rusted surface produces a squeaking sound when rubbing, and reversing changes the contact angle between the pads and discs, making the noise more pronounced. This is a normal phenomenon, more common in cars with semi-metallic brake pads. If the noise is alarmingly severe, it might indicate that the brake pads are worn to the limit and need replacement, or that there is dust stuck in the caliper causing imbalance. It's recommended to drive for a while to let the brake discs clear the rust first. If the noise remains loud, then check the brake pad thickness and disc smoothness. Parking in dry places can help reduce the issue—don’t ignore it to avoid compromising safe driving. Overall, there’s no need to panic, but timely maintenance is essential.
