What Causes the Noise When Braking in Reverse?
2 Answers
Reasons for noise when braking in reverse: When braking in reverse, which is opposite to the vehicle's forward direction, there is a certain amount of clearance between the brake pads and the rear end of the bracket. Therefore, during braking, the brake pads impact the rear surface of the bracket, resulting in abnormal noise. The working principle of braking mainly relies on friction. By utilizing the friction between the brake pads and the brake discs, as well as between the tires and the ground, the kinetic energy of the moving vehicle is converted into heat energy through friction, bringing the car to a stop. To mitigate the noise when braking in reverse, a thin layer of lubricating grease can be applied to the parts where the brake pads connect with the brake caliper bracket. This can help improve the phenomenon to some extent.
I know this issue all too well, having fixed cars for over a decade. That squeaking sound when braking in reverse? Eighty percent chance it's due to metal hard spots on the brake pads, most noticeable during cold starts. It's like having a pebble stuck in your shoe sole—when reversing, the brake pads rub in the opposite direction, causing metal debris to grind against the brake disc, hence the noise. It’s especially louder the morning after rain because a thin layer of rust forms on the brake disc, but a few more brake applications usually quiet it down. If it’s a sharp metal-on-metal scraping sound, check the brake pad thickness immediately—don’t delay replacing them if needed. Last time, my neighbor’s car had worn-down warning pads grinding against the disc, squeaking so loud the whole neighborhood turned their heads during reverse. A pad replacement only cost a little over 300 bucks.
