By February 5, 2014 6 Comments Read More →

Warped Brake Rotors? Why?

warped brake rotorsSo let me guess, you step on the brake pedal in your car and the steering wheel starts to shake back and forth….and it gets worse the faster you go like on the freeway?  I hear ya loud and clear and the problem you have is most likely to do with the front brake rotors on the vehicle.

The brake rotor is a large metal disc that the brake pads grab onto to slow the vehicle down. When the rotors get too thin, or they have been through high water when they were hot they tend to warp. This warpage is what causes the shaking when you step on the brake.

The rotor is no longer smooth and flat, and since it is spinning around just as fast as the tires are any small imperfection on the surface of the rotor will be felt when you step on the brake pedal. Sometimes the warpage is so bad that the brake pedal itself will pulsate up and down.

So if this is happening to you, you basically have 2 options to fix it.

1. Have the front brake rotors machined to make them smooth again, this is called truing and will remove a thin layer of the metal surface to make it smooth and flat again.  problem with this is, it removes part of the metal surface, making the rotor thinner than before and more susceptible to warping easier…again.

Warped brake rotor

This old brake rotor is too worn out to resurface and will need to be replaced.

2. Replace the brake rotors with new aftermarket rotors from your local auto parts store. This is MY recommendation.  Yes, it will cost you a bit more to do the job now but a new rotor has a lot of material on it and will last longer and be less susceptible to warping again, although over time it will just as the original ones did.

Buying from your local auto parts store and NOT the dealer will be much cheaper, and we call those parts “aftermarket parts” since they are not made by the vehicle manufacturer. They are usually just as good, but for a lot less money.

Some repair shops will let you supply your own parts, so they can not mark up the price…this is advisable but you are taking all the warranty on the part by doing so, but its cheaper for you.

Now, with all that said, I would highly suggest you replace the brake pads at this time too. Why?  Those old brake pads are warped if you will just like the rotors since they have been in contact with that out of round rotor surface chances are the brake pads are also not flat and smooth anymore and can produce a shimmy feeling on the brand new rotor.

The whole procedure of replacing the rotors and pads IS in fact a brake job, so in essence that is what you need to have done.

You might have rear brake rotors as well, and in the video I show you a simple way to test to see if the rear rotors are warped too. Repeat the procedure above if that is the case.

Watch this short video to understand more about warped brake rotors and how you can check them yourself.

Austin Davis

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About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."
  • Austin Davis

    Yes….and no…or maybe. Improper wheel torque is a big problem, but so is water. Water, that is pooled up on the exit ramp that splashes up on the super hot brake rotor is the main cause of warp. Excessive heat is the real issue, that heat from the rotor needs to go somewhere, and the rotor sucks up most of the heat transfer. Think expansion and contraction. Thanks for your comment.

  • MotherDawg

    Hi… nice but if “Warped Brake Rotors? Why?” is the question the the answer is mostly wrong.

    I use to work in new car dealership and one of them had communicated to its mechanics what is the main culprit, what makes rotor, new or worn, warp like crazy.

    The expensive investigation revealed… Wheel nut torque !

    Try it out, buy new rotors, torque one nut at something like twice the spec while setting the others barely at spec.
    Before a thousand miles, your rotors are trashed.

    Under the different load7pressure generated by the different torques, the “hat” part of the rotor pulls on the disk itself and with temperature… warp 9.9 coming up.

    The moral of the story, when you get home after having worked done on the car… untighten every wheel nut and retorque them to spec.

    It so easy for the corner guy the check the time on his watch while keeping the trigger on his air gun and rack up the torque on one nut to over 200 pounds. He knows, you’ll be back for new rotors.

    Keep questioning everything…

  • Austin Davis


  • Paul S

    I particularly liked the way you described how to check the rear disc warping using the e-brake. Good Idea!

  • Austin Davis

    Yes, it sounds like it is time to replace them. They are pretty cheap these days from your local auto parts store. I personally buy the cheaper brand names, which seem to be just as good as the more expensive ones. Did you watch my video?

  • Richard H.

    Hello – I have 2003 Dodge Ram 1500. The guy told me that my rear rotors are excessively warped 0.877. I am not sure what is that mean and should I replace it?