You might be asking yourself that question since until recently, most rotors could be re-surfaced more than once and did not need to be replaced.
Isn’t resurfacing the norm?
Up until a few years ago machining or resurfacing brake rotors was the norm. This was done to ensure a flat, even stopping surface for the new brake pads. Today, replacing brake rotors is the norm. This is because they are typically too thin to be machined by the time the brake pads wear out. What’s changed?
Today’s Brake Rotors are Thinner than Before
Brake rotors start out being much thinner than ever before. In the push to increase fuel economy, every pound counts. New rotors can weigh four to five times less than they used to.
The challenge is that the thickness of a brake rotor enables it to dissipate the heat that’s created during braking. When a rotor is too thin, it overheats and warps, leading to an brake pedal pulsation, and in a worst case, brake failure.
When rotors were thicker, they could take the wear from the brake pads, be re-surfaced (machined) and still have enough metal left to dissipate the heat. Today, when they’re new, they are often intended to have one life cycle: to survive one set of brake pads when they are put on the car at the assembly plant.
Brake Pads Made from New Materials
Brake pads today are typically made from ceramic or semi-metallic materials. Semi-metallic pads provide strength and conduct heat away from rotors but also generate noise and are abrasive enough to increase rotor wear. Ceramic pads accommodate higher temperatures with less heat fade, shorter stopping distance, and generate less dust and wear on both the pads and rotors.
They also provide much quieter operation because the ceramic compound helps dampen noise.
Today, many rotors are made from recycled materials, which are lighter and better for the environment than the raw steel used previously. However, they also wear faster and are more prone to corrosion because the metals have already been degraded or deteriorated once before.
The next time you have your vehicle’s brakes repaired and your rotors need to be replaced, we hope you’ll know that no one’s being wasteful, trying to speed the job along or looking to make more money on the brake service. It’s simply because the rotors are too thin to be safe or of any more use to you.
Postle Tire Barn is a family owned tire and automotive shop in Tuscaloosa, AL. We’ve been serving the West Alabama area for more than 36 years. If you have questions about our service, feel free to email us at firstname.lastname@example.org or call us at 205-391-0062.