Mr. Wang, a senior technician with 8 years of experience in the auto repair industry, told the reporter that the vast majority of car owners, and even junior repair personnel, have a misconception: they believe that as long as the friction layer thickness meets the standard and the appearance dimensions match, brake pads can be installed directly on the vehicle. In reality, the original brake pad retainers (commonly known in the industry as retaining springs or limiting springs) of vehicles are made of 65 manganese steel. After 4-5 years of normal use, they will exhibit three types of wear: metal elasticity decay, edge corrosion, and deformation under stress. Retainers that appear intact to the naked eye will experience further reduction in elasticity under continuous braking and high-temperature conditions such as long downhill slopes on mountain roads, failing to securely hold the brake pads in place.
Besides the lack of compatible parts, the problem of substandard brake pad materials remains severe. According to the results of cross-regional brake pad quality spot checks at the beginning of the year, including some imported brake pads sold through cross-border e-commerce platforms, the overall failure rate was close to 50%. The main problems with substandard products are concentrated in the friction materials containing construction waste, ultrafine quartz sand, and recycled scrap iron powder. These low-priced brake pads are generally sold for 80-150 yuan per pair, more than 60% lower than compliant ceramic brake pads. While there may be no obvious abnormalities after short-term use, after 3000-8000 kilometers, problems such as severe blackening of the wheel rims, high-frequency abnormal noises during low-speed braking, and scratches on the brake discs will emerge. More seriously, during continuous braking on long downhill slopes, the surface temperature of brake pads exceeds 350℃. Inferior friction materials will rapidly carbonize, leading to heat fade and brake failure.
Reporters conducted on-site comparisons and disassemblies of compliant brand brake pads and substandard, counterfeit products: Compliant products use original cold-rolled steel backing plates with pre-applied damping rubber on the back. The friction layer and steel backing are bonded using a double bonding process of high-temperature adhesive and mechanical riveting, withstanding 400℃ without delamination. They are equipped with dedicated front and rear wheel retainers; the front wheel features a thickened manganese steel retainer spring for deformation resistance, while the rear wheel has a galvanized retainer spring for rust prevention. Front and rear components are not interchangeable. In contrast, substandard products often use recycled scrap iron for their steel backing, which is only 0.6-1mm thin. This makes them extremely prone to warping and deformation during high-temperature braking. The adhesive used is ordinary household resin, which softens and delaminates at 200℃, posing an extreme safety risk of the brake pad detaching entirely.
In response to the widespread problem of excessive repairs encountered by car owners, the industry association has also released a guide to avoid these pitfalls. Currently, both online and offline repair technicians commonly exaggerate the wear of brake pads, recommending a complete replacement even when the remaining thickness is more than 5mm, and aggressively pushing high-end racing brake pads. According to national standards for motor vehicle brake components, brake pads for passenger vehicles only require a remaining friction material thickness of less than 3mm to meet the mandatory replacement standard. For normal urban commuting, ceramic brake pads have a lifespan of 60,000-80,000 kilometers, and semi-metallic brake pads can last 40,000-60,000 kilometers. Furthermore, it is clearly required that brake pads must be replaced in pairs, left and right, coaxially; unilateral replacement is prohibited. Whenever brake pads are removed, regardless of their external condition, the accompanying retainer and damping springs must be completely replaced; this does not constitute excessive repair.
