What Causes Abnormal Noise When Braking Just After Starting the Car?
2 Answers
The reasons for abnormal noise when braking just after starting the car are: 1. When the brake discs rub, they produce some metal dust, which can cause abnormal noises when braking. This type of noise from the brake pads is a normal phenomenon; 2. Abnormal noise from the brakes indicates that the brake pads have reached their wear limit, causing friction between the brake warning shim and the brake disc, resulting in a metal-on-metal sound. Solutions for abnormal noise when braking just after starting the car: 1. Firmly press the brakes several times or perform emergency braking in an open area, and the situation will improve; 2. It is necessary to replace the car's brake pads in time to prevent any potential hazards.
In winter mornings, my car always makes a 'squeaking' sound when I step on the brakes after starting it. I later specifically looked into it. Most of the time, it's because the brake discs and pads get damp and rust overnight, or the brake pads are too cold, causing the friction coefficient to be unstable when first applied. This is especially noticeable if the car was parked outside in the rain—it usually goes away after driving for a few minutes as the rust wears off. However, if the noise persists after driving for half an hour, it's necessary to check whether the brake pads have worn down to the limit indicator or if the brake discs have developed deep grooves. During the last maintenance, the mechanic measured with calipers and said the brake pads need replacement once they're down to 5mm, otherwise, it could damage the discs and cost more.
