A disc brake assembly consists of brake calipers, brake pads, and brake rotors. Part of any disc brake service includes determining whether or not you need new brake rotors. Brake rotors generally need replacing every 15,000 to 70,000 miles, but the exact number depends on your driving style, brake pads, and vehicle. More on this in a bit.
A word on your vehicle’s brake system:
That friction also wears both the brake pads and brake rotors. Brake pads are disposable – there’s no way to “fix” them, so they must be replaced.
Rotors, on the other hand, have a service life. One set of rotors can last through several sets of pads with proper care. Whether or not they can be replaced depends on their remaining thickness. The technician will measure their thickness, and compare them with the “discard thickness” specified for your vehicle. If your rotors are within spec, they can be machined flat again and re-used. If they are too close to the discard thickness, they must be… well, discarded and replaced with new brake rotors.
Not to worry, though! Rotors for most common cars are relatively cheap. Especially when compared to some of the more exotic ones. A Nissan GTR’s rotors, for example, can cost close to $1000 each!
When Should I Need New Brake Rotors?
As we mentioned before, a brake rotor can last as short as 15,000 miles, or as long as 70,000+ miles, depending on your brakes and driving habits. One way you’ll know it’s time for a brake inspection is by remembering “VIBE”
Vibrating Steering Wheel – If you feel pulsing in the brake pedal, and/or vibration in the steering wheel when slowing down, one or more rotors may be warped.
Intermittent Screeching – This is usually the first sign you’ll notice that your brakes are worn.
Blue Rotors – Rotors that have been overheated will have a telltale blue coloration.
Excessive Wear – Inspect your rotors for grooves or scoring (which can cause the screeching we mentioned earlier).