[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index] Rotor Stuph
Phil and/or Judy Rose said, in response to Fred Munro's comments: I've heard others also voice an opinion that resurfacing rotors is inadvisable. When I hear it from a repair shop, my suspicion is always that the _replaced_ rotor is simply a nice, profitable part of a brake job. But I wonder is it possible that bad results are sometimes just from improper turning procedures? (Too much taken off, dull cutter ...). I can't offer much experience, pro or con. A comment about rotors - which some on this list could provide more easily than I, so I beg your indulgence - but think about the functions of rotors, which are to: 1) Provide friction for stopping; 2) Dissipate the heat generated by that stopping friction. Relative to turning rotors, #2 is most important. The more mass you dump heat into, the less that mass will be affected (temperature rise, thermal distortion..). As rotors wear down, there is a minimum mass (functionally easured in rotor thickness) required to deal with the heat. If you are marginal or drop below that mass, two things can happen: 1) The rotors will get hot enough from repeated uses that they may become SO hot that the brake pad surfaces liquefy on contact, creating MUCH less stopping power than normal. This is the cause of "brake fade" with hot brakes; 2) The rotor will warp from the excessive heat. Unlike some cars, Audi minimizes the thickness of the rotors to reduce the total weight of the wheel assembly - and in the process, makes the rotors thin enough that they do not recommend they be turned. Ever. They recommend replacement along with the brake pads. Pushing the limits on this equation is more likely to result in brake fade, rotors warping, etc.; the more agressive the driving, the more likley the result. I'm with Fred - change them and pay the $$. Just don't buy them from the dealer and you'll spend half as much (or less) on the parts. ******************************************************* Al Powell Voice: 409/845-2807 107 Reed McDonald Bldg. Fax: 409/862-1202 College Station, TX 77843 Http://agcomwww.tamu.edu/agcom/satellit/alpage.htm *******************************************************
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