What Causes Brake Friction Noise?
3 Answers
The causes of brake friction noise may include excessively hard brake pads, worn brake pads down to the backing plate, excessive wear of brake discs or drums, rusted brake calipers, stiff parking brake cables, slow return of the master cylinder, etc. It is necessary to visit a 4S shop for inspection and repair. Below is an introduction to brake pedal operation: 1. Introduction to brake pedal operation: Automobile brake pedal operation can be categorized into gradual braking (i.e., anticipatory braking), emergency braking, combined braking, and intermittent braking. Generally, during gradual braking and emergency braking, the clutch pedal should be fully depressed before the wheels lock up and the vehicle comes to a stop, to prevent the engine from stalling and facilitate speed readjustment. 2. Proper timing and force application in braking: Under normal circumstances, avoid stomping the brake pedal all at once. First, press the brake pedal, adjusting the foot pressure (i.e., increasing the force) as needed—apply quick and firm pressure when the speed is high, and light and steady pressure when the speed is low. Then, adjust the pressure increase or decrease based on various conditions.
I've been driving for almost 15 years, and brake squealing is all too common. Most of the time, it's because the brake pads have worn thin. When they wear down to a certain point, the metal indicators inside will scrape against the brake discs, producing that unpleasant grinding noise. Sometimes, it's due to water or rust on the brake discs, especially noticeable in damp weather—like when driving after rain. Another possible cause is small stones or debris getting stuck in the braking system. Once, my car made a piercing squeal on the highway, and the mechanic found a pebble lodged in there. Don’t ignore it—this can reduce braking efficiency and increase the risk of skidding during emergency stops. I recommend checking the brake pad thickness at least once a year, or heading to a reliable repair shop as soon as you hear the noise. It’ll save you from costly and dangerous brake disc replacements later.
From the perspective of brake system design, friction noise is usually caused by component mismatch or wear. For example, when brake pads reach the end of their service life, residual hard materials scraping against the brake disc can produce noise; if it's a new car or newly replaced brake pads, initial break-in may also temporarily cause noise. Additionally, dust accumulation, moisture evaporation, or uneven brake disc surfaces can all trigger friction. I recall that some high-performance brake pads, while offering excellent braking, are prone to noise due to material properties, requiring more frequent use of cleaning agents to remove dirt during maintenance. For prevention, avoid sudden braking to reduce wear and perform regular full-vehicle inspections, especially before and after the rainy season. Long-term neglect can lead to brake disc damage, doubling repair costs, so it's best to seek professional diagnosis to ensure no hidden risks.
