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Discussion Starter · #1 ·
I noticed a while ago that I was getting vibrating coming from the front end, but not all the time. I finally figured out what it is. The front rotors are heating up after I drive a while if I am doing alot of hard braking, and the rotors are warping. Once they cool down the problem is gone. Both sides seem to be doing this (there is no pulling to one side). I recently changed to a larger master-vac, which may be exacerbating the problem, but it was doing this before too. Why is this happening? Are the callipers sticking? If so, what is the fix? If not, what else could be causing the rotors to heat up so much?
 

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Time for a physics lesson. First though, no gum chewing in class! Seriously, I think that I might know what your problem is.
Your brake rotors have mass. One of the purposes of this mass is to absorb heat from your pads. As the rotors get worn down and turned they actually have less mass. Because they have less mass they can absorb less heat and when they do which is all the time when you drive they get hotter. Usually the symtom that people describe with rotor warp is a wobbling sensation at slow speed stopping and a vibration at higher speeds. I cooked a set of rotors on a 76 280Z in only two laps of Brainerd International Raceway! The cure is to replace the rotors with new. Fortunately, even crossdrilled rotors are fairly cheap ($69.00 at NOPI) These new rotors will have more mass and be able to absorb more heat. Now if your problem is fade too then you must completely bleed your brakes. This should be done every year anyway. Lesson over, class dismissed.
 

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Discussion Starter · #3 ·
Thanks for the response. Is it possible the calipers are sticking? I guess not, since the problem is non-existant if I stay off the brakes and slow the car solely by down shifting. If the calipers were sticking, they would do so the first time I hit the brakes, and then they would heat up. Also, it's unlikely that both sides would stick equally. You are probably right, the rotors are probably worn down.

Should I go with stock rotors, or go with cross-drilled. The cross-drilled are only at most $100 more per pair, so if they give better performance, I don't see why you would not want to go that way.
 

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<b>RE: Help!! Front Brakes overheating!</b>

Coop, I sold the powerstop crossdrilled rotors in my store for a year and a half, and every single pair that I ever sold came back with fatigue cracks in the hole areas. Supposodly the powerslot rotors cure the cracking but the company that makes them (Autospecialty in NJ) says that the slotted rotors warp easily, due to the decreased thickness in the slots. My advice is to purchase a good thick set of USA or Japan made rotors and have them cryo treated. Racers in my area use cryo treating and have no warpage after tens of races.
 
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