What Causes the Squeaking Sound When Braking a Car?
2 Answers
Causes of squeaking sound when braking a car: 1. Rust or dirt on the brake disc or brake pads; 2. New cars may produce noise when braking, as new brake pads and discs require a break-in period; 3. Excessive wear of brake discs or brake pads; 4. Installation issues, such as incorrectly installed brake pads or mismatched models. Many small cars feature front disc and rear drum brakes, which experience significantly reduced braking performance after driving through water. When the wheels rotate, centrifugal force causes water droplets on the disc to disperse automatically, not affecting the brake system's functionality. Drum brakes on cars consist of a brake fluid pump, pistons, brake shoes, and a drum chamber. During braking, high-pressure brake fluid from the wheel cylinder pushes the pistons to apply pressure on the two crescent-shaped brake shoes, pressing them against the inner wall of the drum chamber, using friction to stop the brake drum from rotating and achieve the braking effect.
I drive an old car, and the brakes always squeak when I press them. At first, I thought it was a mouse squeaking! Later, I realized that the noise is most likely due to severely worn brake pads. Over time, brake pads become thinner, and they have wear indicators that produce a metal-on-metal scraping sound when they're nearly worn out, signaling that they need replacement. It could also be due to rust on the brake rotors or small stones stuck between the pads and rotors, which usually wear off after driving a few dozen kilometers. If left unaddressed, not only is the noise annoying, but braking performance also declines, making it dangerous in emergency situations where the brakes might fail. I recommend checking the thickness of the brake pads—if they're thinner than 3 millimeters, it's time to replace them. Regularly clean dust from the braking components during maintenance, especially after the rainy season. Safety comes first—don’t delay too long. It’s best to save money and hassle by visiting a repair shop.
