Whatever kind of car you own, you’ll probably eventually need the brake rotors replaced. Brake rotors, also called brake discs, are what your brake pads clamp against in order to stop your car when you push the brake pedal. If your car’s brake pedal is pulsing when you stop at a high speed, your rotors are probably warped. This is often accompanied by a wobbling in the steering wheel. Even if they’re not warped, they will inevitably wear out. Modern metal brake pads grind against the rotors, creating “brake dust” that consists primarily of iron. When the pads are swapped out, you may need to swap out the rotors too.

  • You probably need to replace your brake rotors soon if:
  • Your car emits a high-pitched squealing sound when you brake
  • You hear a loud, grinding, metallic sound when braking
  • Your brake feels nonresponsive
  • Your car pulls to one side when you apply the brake
  • When you brake, you feel something vibrating or pulsating in the pedal, the steering wheel, or the seat

If you’re into working on your own car, swapping them out yourself can be rewarding. But you may have some dificulty figuring out what size brake rotor your Audi actually needs. New Audis have quite a few different options, and this includes the brakes. An Audi can have any of a variety of brake rotor sizes, brake codes, hat heights, and brake pad setups, making it challenging to figure out your brake rotor size. If you’re shopping for new rotors, these helpful tips can help you identify the right size for your Audi.

1) Figure out the brake rotor part number.

After removing the wheel, you may be able to find the old rotor and identify the part number. This only works if they’re the original brake rotors. If you’ve had them replaced in the past, the part number won’t be there, and you’ll need to find another way to identify it.

2) Contact your dealer with your VIN.

Your VIN can enable you to find the brake code. If you call your Audi dealer, you may be able to find out what brake code corresponds with it. Only an authorized dealer will have access to this information. An independent parts specialist won’t.

3) Measure the outside diameter of the rotors.

If you’re still having trouble figuring out your Audi’s brake code, try measuring the outside diameter of your existing brake rotors. Simply flip the rotor onto its back and measure all the way across.

4) Measure the hat height

Along with the outside diameter, you may also need to find out the hat height. Before measuring, clean off any rust or scale buildup. Then, holding a gauge across the brake rotor hat, measure the distance from the face to the hat height gauge, starting at the innermost edge.

Once you’ve figured out the right size for your Audi, you can order the right part. Brake rotor replacement is a fact of life for car owners, and putting new pads on a bad rotor will only make the problem worse.