What Causes Sharp Noise from Brake Pads?
2 Answers
Causes of sharp noise from brake pads include: issues with brake pad material, uneven wear of brake discs, and brake pump failure. Below are relevant details: 1. Braking System: A car's braking system consists of a vacuum booster pump, master brake cylinder, wheel brake cylinder, brake pads, and brake discs. When the driver presses the brake pedal, the vacuum booster pump provides assistance, making it easier to press the pedal. After pressing the brake pedal, the master brake cylinder uses brake fluid to push the wheel brake cylinder, which then presses the brake pads against the brake disc, converting kinetic energy into heat energy and slowing the car down. 2. Regular Replacement: Brake pads and discs are wear-and-tear components that require periodic replacement. As the car's mileage increases, both the brake pads and discs wear down. When they reach a certain level of wear, they need to be replaced. Brake fluid in the braking system also requires regular replacement. Brake fluid is highly prone to absorbing moisture. If the moisture content in the brake fluid is too high, it can reduce braking force and increase stopping distance. When the moisture content reaches 3%, immediate replacement is necessary.
While driving, I've encountered the sudden, sharp squealing noise from brake pads several times, which really startles me. There's actually more than one reason for this: the most common is when the brake pads are worn to their limit, exposing the wear indicators inside, which then directly rub against the brake disc, acting like an alarm to remind you they need replacing. Another possibility is that something gets stuck between the brake pad and disc, like a small stone, rust, or dirt—this often happens after rain or when the car has been parked for a while, causing the brake disc surface to rust. Also, the quality of the brake pads themselves could be an issue, such as uneven material composition leading to localized hardness that causes squealing during friction. Don't forget installation problems; if the shims weren't positioned correctly or the caliper was misaligned during the last maintenance, it could also lead to abnormal noises. If not addressed promptly, not only is the noise annoying, but it can also accelerate brake disc wear and even affect braking performance. That's why I always recommend getting it checked as soon as you hear the noise—don't delay.
