Warping discs every 5k


#1

Having gone through two sets of rotors, I finally found a mechanic who changed my pads to non-metallic.


#2

???

100% of the inertial energy of your vehicle is converterted to heat energy when you stop. The portion of the heat that’s dissipated by the rotors, most of the heat, does not change with the pad material. Beyond that, the differences in different types of pads are more differences in the material blends than anything else. “Nonmatallic” pads actually still have metal in them, typically copper, but in smaller portions.

For these reasons, warping rotors are a generally considered a rotor problem rather than a pad problem. Have you been “turning” (machining) and reusing your rotors? Has whoever does your work been using a torque wrench on the installation including on the remounting of the wheels? Have you been using cheap Chinese rotors?

If the new pads worked for you, I’m truely happy for you. I’m only posting because I’m wondering of the pads were, in fact, the problem.


#3

I too question whether or not the rotors were “turned”. I no longer have rotors on any vehicle turned because the result is usually rotor warping. I just buy quality brake rotors and torque all lugnuts with a torque wrench. Airgun torquing with or without torque sticks is verboten in my opinion. Brake pads have little to do with rotor warping unless the brakes are sticking or you ride the brake pedal.


#4

My guess is that the OP will be back. But I appreciate his post, even though the context is nonexistant. A new friend is always a good thing to have.


#5

Have you been using cheap Chinese rotors? That would be my first guess, then I would condor someone not using a torque wrench.


#6

It is very hard to say what the heck this was about. Presumably the OP has been given some info that his rotor problems involved the pads. I have no idea whether it has to do with the pad material or not, but sometimes those brake pulsations can be from pad deposits on the rotors rather than any kind of warpage in the rotor itself. (And by saying that I am not saying “rotors don’t warp” - I know that has been contentious. I’m sure rotors do warp. But I’m just as sure that not all brake pulsation is from warpage).

Anyway, it is plausible that cheap or incorrect brake pads can cause problems just like cheap rotors can by being more likely to leave deposits that produce unevenness on the rotor surface and then develop hot spots leading to further uneven wear on the rotor surface.


#7

An excellent point Cig.
And I’d also add the question “were the rotors cleaned with a cleaning solvent (disc cleaner) before installation”?

Just in case the OP returns…


#8

The OP may be commenting on a segment of the show today where a guy was having warped rotors every 5,000 miles. The guy on the show was having his rotors machined every 5K.


#9

I think that warping is often due to using an air wrench to over-torque to lug nuts.


#10

Possibly at tire rotation time.


#11

I had a '98 Volvo V70XC wagon that warped rear disks regularly. All it seemed to take was one hard stop. It needed rear brakes and rotors pretty close to every 5K miles. You don’t mention the car these rotors are installed on, but some cars just eat rear brakes.