Do I Need to Replace Brake Pads When Changing Brake Discs?
3 Answers
Replacing brake discs does not necessarily require replacing brake pads. If the brake pads are still thick, you can change the brake discs without replacing the brake pads. Generally, brake discs need to be replaced once for every two replacements of brake pads. When the combined depth of the grooves on both sides of the brake disc exceeds 3 millimeters or the edges of the brake disc become sharp, it is time to replace them promptly. The method for replacing brake discs is as follows: 1. Check the wear level of the brake disc; if there are grooves deeper than 3 millimeters on the brake disc, it can be replaced; 2. Remove the front wheel tire to reveal the round disc, which is the car's brake disc; 3. Remove the screws fixing the brake caliper, take off the old brake disc, install the new brake disc, and then reattach the brake caliper.
I've been repairing cars for over a decade and often encounter this question from car owners. Theoretically, when replacing new brake rotors, you don't necessarily have to change the brake pads as long as they still have sufficient thickness. However, in reality, the mismatch between old and new components can cause issues. The old pads may have surface pits or material buildup, which when pressed against the smooth surface of new rotors, can lead to squeaking noises and less smooth braking. Worse still, this uneven friction accelerates wear on the new rotors, potentially causing problems within months and leading to additional repair costs. Therefore, I recommend checking the remaining thickness of the pads when replacing rotors—if more than half is worn away, it's most cost-effective to replace them together; if they're still relatively new, you can save some money. Regular maintenance of the braking system extends your vehicle's lifespan—never cut corners when it comes to safety, as it's the top priority.
I'm just an ordinary office worker who's been driving a family car for over a decade, always trying to save money on repairs. When replacing brake rotors, I don't think it's necessary to change the brake pads as long as they aren't too worn. For example, if most of the pad thickness remains, you can remove them, clean them up, and reuse them with new rotors. However, there are quite a few downsides: the contact surface of old pads isn't compatible with new rotors, leading to a stiffer brake feel initially and sometimes loud noises when stopping at red lights. Additionally, used pads accumulate impurities that can scratch the new rotors, causing grooves and requiring replacement sooner, which ends up costing more. My wife always advises me not to be too stingy, so I've developed a habit of measuring pad thickness whenever I change rotors to avoid risks. Regular maintenance checks are affordable and give me peace of mind.
