What Causes the Squeaking Sound from Brake Pads?
3 Answers
Brake pads produce a squeaking sound due to the following reasons: 1. Severe wear of the brake pads, reaching the warning line or being completely worn out; 2. Deterioration in the quality of the brake pads; 3. Improper installation of the braking system causing abnormal noise; 4. Presence of foreign objects in the brake pads or rust on the brake disc. Brake pads, also known as brake linings, are critical safety components in a car's braking system. The effectiveness of all braking relies heavily on the condition of the brake pads. Brake pads typically consist of a steel plate, an adhesive heat-insulating layer, and a friction block. The steel plate is coated to prevent rust, and the coating process is monitored using an SMT4 furnace temperature tracker to ensure temperature distribution during the coating process, thereby guaranteeing quality.
It's quite common to hear squeaking noises when stepping on the brakes recently, usually due to minor friction or debris caught between the brake pads and rotors. As someone who frequently tinkers with cars, I've found there are many possible causes—newly replaced brake pads may produce a breaking-in sound for a few days, which typically fades within a week. If it's old brake pads, they've likely worn down to the limit, causing the embedded metal shims to scrape against the rotor and produce noise—a clear sign it's time for replacement. Sometimes, driving frequently in rainy weather can cause the rotors to rust or trap small stones, resulting in sharp squeals when braking. In such cases, find an open area and perform a few hard stops to try dislodging the debris. However, if the noise becomes increasingly harsh or the brake pedal feels softer, don't ignore it—this could affect braking distance. It's best to visit a repair shop to have a mechanic check if the brake calipers move freely or if the rotor surface has developed grooves. Replacing pads yourself isn't difficult, but improper installation can also cause noise.
A squealing noise when braking is mostly caused by issues in the braking system. Simply put, your brake pads have worn down to the metal wear indicators, which are designed to alert you that it's time for new pads—the metallic scraping sound is harsh but effective. It could also be that the chamfer on new pads hasn't worn in properly, and the noise should disappear after driving a hundred kilometers or so. Other common causes include rust on the rotors due to damp weather or dust and hard particles trapped in the brake caliper slots. These issues can often be resolved by driving to a safe area and performing a few hard stops, which usually does the trick. However, if the noise persists for a week or two and is accompanied by vibrations in the car body, it's time to be cautious—this could indicate warped brake rotors or a stuck caliper piston, which can cause dangerous pulling during high-speed braking. My neighbor ignored this once and ended up discovering cracked rotors when replacing the pads. Inspection fees for regular family cars aren't expensive, and a professional repair shop can diagnose the issue in about ten minutes by removing the wheels.
