Why is there a strange noise when braking while reversing?
2 Answers
The reason for the strange noise when braking while reversing is due to the moving caliper hitting the caliper bracket during the reverse process. Below are the relevant explanations: 1. Radar system: When the car moves from the warning zone into the danger zone, the radar system automatically activates the braking device to control the car's reverse movement. The principle is based on an ordinary reverse radar system, with the addition of a servo mechanism that has a braking function. When the car moves from the warning zone into the danger zone, the controller sends a control signal to the braking servo, which immediately activates to automatically stop the car from moving backward, ensuring safe reversing. 2. Braking: When driving forward and braking, there is no 'play gap' at the lower connection point with the brake bracket, so no noise occurs. However, when braking in reverse, the brake caliper moves upward and hits the upper bracket, producing the strange noise.
I often encountered this issue when repairing cars. Many people experience squeaking sounds when braking in reverse, mainly caused by changes in friction within the braking system. When reversing, the contact direction between the brake pads and rotors reverses. Normally, forward motion causes wear in one direction, but in reverse, it creates opposing friction, which can scrape off accumulated dust or rust, resulting in noise—especially in humid weather or after prolonged parking. If a new car makes such noises, it might be due to overly hard brake pads or insufficient break-in, which should improve over time. For older cars, pay attention to brake pad wear—if they're too thin, not only will they squeak, but braking performance will also suffer. Just last week, a friend's car made a clunking noise in reverse. After inspection, I found rust on the brake rotors, and a quick sanding fixed the issue. I recommend regularly cleaning the braking system to prevent minor issues from becoming major hazards.
