Is it necessary to replace brake pads when changing brake discs?
3 Answers
Replacing brake discs does not necessarily require replacing brake pads. If the brake pads still have sufficient thickness, they can be retained when changing the brake discs. Using high-quality brake discs can ensure a service life of 80,000 to 120,000 kilometers. Before replacing brake discs, it is essential to check whether the new discs are genuine parts, verify the integrity of the product packaging, confirm that the anti-counterfeiting marks and packaging labels match those on the brake discs, and ensure that the product model corresponds with the certification. Brake discs produced by reputable manufacturers feature clear packaging prints, including license numbers and execution standards, and the packaging box contains certificates of conformity, production batch numbers, and manufacturing dates. Using counterfeit or substandard brake discs may provide temporary braking performance, but prolonged use can cause the discs to deform due to high friction temperatures, reducing braking efficiency and ultimately compromising driving safety.
Replacing brake discs doesn't necessarily mean replacing brake pads, but it depends on the situation. Last year when I sent my car for maintenance, the mechanic said the brake discs were worn through and needed replacement. At that time, the brake pads were still thick, so I didn't replace them. I saved a few hundred bucks, and it was fine for the first few months. But later, there was a screeching noise when braking. Upon inspection, it turned out the old pads were wearing unevenly and didn't match well with the new discs. From a safety perspective, if the pads are still new and not worn thin, you can keep them. But you must measure their thickness - they should have at least 3mm left. Otherwise, old pads can damage new discs, increase braking distance, which is dangerous at high speeds. I've developed a habit of checking them regularly during maintenance. If the pads are getting thin, I replace them together to avoid making two trips to the shop.
Having driven for over a decade myself, I believe this should be handled flexibly. When replacing brake rotors, it's not mandatory to change the brake pads simultaneously—the key is balancing cost-effectiveness with practicality. That time, I only replaced the rotors since the pads were fairly new and in good condition, so I left them untouched. However, be aware that pairing new rotors with old pads may increase friction intensity, potentially causing premature pad wear or unusual noises. In the long run, if the pads are nearing their end anyway, replacing both together is more economical, saving additional labor costs and avoiding repeated disassembly. Checking pad thickness is straightforward—use a small measuring tool or get a free evaluation at a shop. Never compromise on safety: severely worn pads must be replaced to ensure responsive braking.
