I have an '07 Fit Sport. My brake rotors are constantly warping. I've had them machined a few times, and I bought new $25 ones from the local auto store. I've replaced the rotors themselves and rotors and pads at the same time. I've found them online for a lot more money and made out of different materials. Do more expensive rotors really help prevent warping?

 

Your rotors could be glazed. Did you " bed-in" your new brake pads/rotors when you got them installed?
Bed-In Instructions
I thought my rotors were warped, but was fine after performing this procedure with a new set of Hawk HP Plus pads. I learned this trick from SCCA AutoX Champ, "mrFroge."

 

How are you determining that the rotors are warped? Did you or a shop check rotor runout with a dial indicator or are you just going off pedal vibration? If the latter, i'd verify that it is indeed the rotors warping and not what Macbuddy said, improperly bed pads.

If your rotors ARE warped, there may be another problem causing this and causing your rotors to overheat and warp, i'd check for sticky calipers.

Another possibility is that indeed the rotors were simply defective, in which case a better quality rotor may be in order, i'd suggest Brembo, just get the blanks, not the slotted/crossdrilled/diamond or whatever.

 

Besides what macbuddy and Wanderer already pointed out, I'm curious about your brake-use/braking habits. Buying expensive rotors might not necessarily solve your issues. It all depends on intended use and driving habits. Just my take.

 

macbuddy and Wanderer covered the tech, Subie may have hit on the root cause....

Even my OEM brakes have survived heavy abuse for 60+K (I brake LATE and HARD) and a full season of AutoX. They did get glazed, but I turned that off.

Brembo blanks aren't a bad suggestion at all. Avoid any type of drilled rotor, they can crack and will effectively act like a cheese grater and significantly decrease your pad life!

 

Yes, better metals do avoid warping. If your rotors are from China you can be sure they are cheap iron and easily warp. Suppliers like Bremco are much less likely to warp and offer better friction coefficients to the better brands of pads, like Hawk.

 

Thanks for the suggestions. I do tend to drive pretty aggressively, so my driving habits may be part of the problem. But I've never heard of bedding in the rotors and brake pads. I've always assumed the rotors were warped because I could feel the brake pedal pulse, I've not had a shop test them. But I also probably have rotors made in China. They cost $25 at Autozone, so they can't be the best material.

 

I had the same feeling on a spirited drive recently, try bedding them in. After a couple hard braking into a few turns my pulsating brake pedal went away!

 

Dumb comment but... Make sure it's not the ABS you feel, I remember with stock wheels and tires the ABS would come in alll the time and make that audible pulsating sound too

 

"bedding' is primarily for pads, not rotors.
In spite of what many may assume, bedding brake pads is not for getting the pads to conform to the rotor but to heat the pads to finish 'baking' the material. Failure to do so often leaves the fresh face a trifle soft and wears away easily. That also reduces braking ability and can lead to coating the rotor in places, not uniformly, and that often is assumed to be warped rotors..

 

That pulsing feeling that is typically thought of as warped rotors, can more likely be pad judder... This happens at very high and low temperatures especially when dragging the pads or at a stop...

And yes, bed in your stuff...