Brake Squealing And Weak Braking Power? Be Alert To These 4 Common Brake Pad Faults

"Every time I step on the brakes, I hear a 'squeaking' sound-could that mean there's a problem with the brake pads?" Recently, many car owners have voiced similar concerns on automotive forums. As temperatures fluctuate and vehicle usage increases, brake pad malfunctions enter a high-incidence period. Reporters interviewed automotive repair facilities and industry experts to summarize four common types of brake pad faults and their corresponding solutions, helping car owners avoid safety risks.​

Fault 1: Frequent Brake Noises​

This is the most noticeable issue for car owners, mainly categorized into two types: "high-pitched scraping sounds" and "dull thudding sounds". Wang Lei, Technical Director of an auto repair shop in Beijing, explained that if a continuous high-pitched sound accompanies brake application, it is mostly due to brake pads being worn down to their limit-where the wear indicator in the friction block comes into contact with the brake disc. At this point, the brake pad thickness is usually less than 3mm, and immediate replacement is required. If a dull thudding sound occurs, it may indicate loose brake pad fixing bolts or abnormal brake calipers. Ignoring this for a long time can lead to uneven brake pad wear and even brake caliper seizing.​

"Once, a car owner ignored the noise, which resulted in the brake pads wearing through the brake disc-repair costs jumped from a few hundred yuan to over 3,000 yuan," Wang Lei warned. Do not delay when abnormal noises occur; a preliminary judgment can be made through a "visual inspection": after removing the tire, check the brake pad thickness. If the wear difference on one side exceeds 1.5mm, the brake calipers should also be inspected for jamming.​

Fault 2: Significantly Reduced Braking Power​

The feeling of "a soft brake pedal that needs to be pressed deeper to stop the car" is often related to degraded brake pad performance, or air or fluid leaks in the braking system. Industry data shows that over 60% of cases involving reduced braking power are caused by decreased friction coefficients due to damp or heat-aged brake pads. Particularly in rainy areas, rainwater seeps into the gap between brake pads and discs, temporarily reducing friction performance. In such cases, use the "pulsed braking" method (lightly tapping the brake pedal) to dry the moisture using heat generated by friction, restoring braking power.​

If reduced braking power is accompanied by a "spongy" feel in the brake pedal, it may indicate insufficient brake fluid or air leaks in the pipeline. Promptly check the brake fluid level, top up with standard-compliant brake fluid (e.g., DOT4, DOT5.1), and inspect the pipeline for tightness to prevent accidents caused by brake failure.​

Fault 3: Vehicle Vibration or Pulling During Braking​

Steering wheel vibration or vehicle pulling to one side during braking is often caused by "uneven brake pad wear" or deformed brake discs. Mr. Li, a car owner in Guangzhou, once encountered this issue-inspections revealed that the left brake pad was 3mm more worn than the right. "Long-term one-sided parking and frequent hard braking can cause uneven force on brake pads, leading to uneven wear," he noted.​

Resolving this issue requires two steps: first, replace unevenly worn brake pads. If there are obvious grooves (depth exceeding 0.5mm) on the brake disc surface, resurfacing the disc is necessary. Second, check the front wheel alignment parameters and adjust the front wheel toe-in and camber to prevent aggravated brake pad wear due to misaligned wheels.​

Fault 4: Brake Pad Overheating, Smoking, or Burnt Smell​

After long-distance driving in summer, if a burnt smell is detected from the brake pads (or even smoke is visible), stop the vehicle immediately for inspection. This fault is mostly caused by poor brake pad heat dissipation or "dragging brakes" due to stuck brake caliper pistons-where brake pads remain in contact with discs for extended periods, generating excessive heat. Do not cool the brake disc with water directly; allow it to cool naturally. Afterward, check if the brake caliper pistons retract normally; replace the piston or dust boot if necessary.​

Expert Tips: Daily Maintenance and Fault Detection Essentials​

Zhang Min, a braking technology expert at the China Society of Automotive Engineers, advised car owners to maintain brake pads through the "three-step check: look, listen, test":​

Look: Check brake pad thickness (new pads are approximately 10mm thick; replace when below 3mm) and whether the brake disc surface is smooth.​

Listen: Pay attention to abnormal sounds during braking.​

Test: Verify if the brake pedal travel is normal (a noticeably lower pedal may indicate brake pad wear or brake fluid leakage).​

Three key principles for brake pad replacement:​

Choose products from formal brands, check production certifications and anti-counterfeiting labels on packaging, and avoid "three-no" (no brand, no certification, no manufacturer) products.​

Replace brake pads on both sides simultaneously to ensure balanced braking power.​

"Break in" new pads: Avoid hard braking within the first 100km to ensure full contact between pads and discs.​

Additionally, brake pad replacement cycles vary by vehicle type: Family sedans typically require replacement every 30,000–50,000km; for SUVs (due to greater vehicle weight), inspection is recommended every 20,000–40,000km. Vehicles frequently driven in mountainous areas or congested roads experience faster brake pad wear and require shorter inspection intervals. "Brake pads are the 'last line of defense' for driving safety," Zhang Min emphasized. "Never ignore faults to save costs-timely repairs prevent minor issues from escalating into major accidents."