How to Check Brake Discs

Written by ki west
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Check Brake Discs
Check the brake disc rotor to see if it's smooth or grooved. (disque de frein image by Christophe Fouquin from

The brake disc rotor is the silvery part that the brake pad literally pushes against to stop the vehicle. Often when you get a brake job, the disc rotors are fine and nothing needs to be done to them. Sometimes though they need to be turned--a process that literally shaves off some of the metal around the rotor to make it smoother. Turning the disc brake rotor makes the rotor thinner, which can affect its structural integrity.

Skill level:

Other People Are Reading

Things you need

  • Micrometer
  • Lug wrench

Show MoreHide


  1. 1

    Press on your brakes when driving down the road at about 40 miles per hour. Vehicle shaking can indicate a front brake disc rotor is too thin. Shuttering of the steering wheel can indicate a warped rotor and can cause the entire vehicle to shake quite violently.

  2. 2

    Look through the wheel (if possible) and into the brake disc rotor, which should be somewhat shiny and silvery without obvious rust. Removing rust from the brake disc rotor can't be done easily. Replacing the rotor might be necessary.

  3. 3

    Look through the wheel (if possible) and into the disc rotor, which should be smooth. Observing ridged areas with up and down grooves can indicate brake disc rotor problems.

  1. 1

    Raise the vehicle with a jack. Remove the lug nuts by placing the lug wrench on each lug nut and putting your body weight into each turn, counterclockwise. Place the lug nuts you remove in a hub cap, if one is available, or somewhere out of the way. Grab the tire firmly and pull it off. Lay it under the vehicle, close to where the tire was taken off. Place a large, thick block of wood or a hydraulic floor jack under the vehicle for extra safety.

  2. 2

    Measure the thickness of the brake disc rotor with a micrometer. Turn the disc rotor to get eight different measurements. Measured thickness varies with vehicles, therefore, check the specifications for your car. Replace the rotor if it falls below minimum thickness.

  3. 3

    Run your hand over the brake disc rotor. Grooved areas can be measured using the micrometer. Measure eight different positions on the brake disc rotor, turning the rotor as each measurement is taken. Varied measurements can indicate that you need to replace the brake disc rotor or get it turned. Uneven wear can adversely affect your stopping ability.

  4. 4

    Test for a warped brake disc rotor using a micrometer. Place the micrometer on the rotor. Measure eight different positions on the brake disc rotor, turning the rotor as each measurement is taken. Varied readings that are slightly different can indicate that the rotor overheated and has become warped, causing your vehicle to shutter when stopping.

Tips and warnings

  • The AutoZone website provides specification thickness of brake disc rotors for most vehicles.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.