First time vette owner and experiencing chronic warping rotors on my 1999 C5. Other vehicles I currently drive include: 1995 GMC 1500 P/U, 2002 chevy trail blazer, 2000dodge intrepid. No brake problems with these other cars...ONLY WITH MY VETTE. After carefully tracking the mileage, it seems to occur every 6,000-10,000 miles. Dealer turned 3 time within first 2 years and warrentied front rotors once (almost 7500miles ago). Now they feel warped again. any suggestions?

 

Throw away the old warped rotors and buy a new set. When you turn them they are thinner and more prone to warp. The most important thing is the torque on the wheel lug nuts. 100 ft lbs is the magic number. Properly torquing the lugs is the key. Make sure that the tech doing the work uses a torque wrench and not just an impact gun.

 

And buy aftermarket rotors. If you buy the GM rotors, you'll have the same problems down the road.

 

As many people have pointed out I don't think rotors really warp but rather have uneven material build up: http://www.stoptech.com/whitepapers/...otors_myth.htm

I have seen sevreral people show up at the track with "warped rotors" that cured themselves after some hard runs! Many in the old days of non ventilated single plate rotors but not anymore. As I have mentioned before our local machine shop guy who turns a tons of rotors says he doesn't see them. I'm on my second set of GM OEM rotors with lots of track time and no warped rotors.

 

This is the reason GM did away with the wheel locks mid-run of the C5 2002 MY. It seems the dealers, who install the locks - not the factory, were prone to using impact wrenchs when putting the locks on. This is the single biggest reason the rotors develop run-out problems.

My rotors (all 4) developed the problem after the first 3500 miles of incredibly easy-easy braking. I was stunned. They were turned by the dealer (same dealer who created the problem) under warranty (for which GM reimburses them - see a pattern here?)

I had a lengthy conversation about rotors with one the Corvette Engineers last April during the 50th AE Press Event at the Indianapolis Motor Speedway. After that conversation, I have no doubt that the run-out problems are caused by OVER or UNDER TORQUING the lug nuts.

They should be torqued in the "star pattern" three times for each wheel, 50lbs, 75lbs, and then the final 100lbs. How many "wrenches" are gonna actually do this?

Either find a good mechanic/dealer who will do this, or get yourself a torque wrench and do it yourself. Keep in mind that retorquing a wheel/rotor that already has lateral run-out will do nothing whatsoever to "fix" it. Only 'truing' or turning can fix that.

My "turrned" and properly torqued rotors have over 7000 miles on 'em and are dead-solid-perfect, even after some incredibly hard "both feet on the brake pedal" stops to check the ABS and impress friends, and myself.

Most of the aftermarket rotors that are of two-piece design (esp. floating hat types) should be fairly immune to the torque sensitivity, and thats why they seem to be "warp proof".

 

Ditto on the stoptech white paper.

Torque is easy to check/set yourself. Just go down to Sears or wherever and buy a torque reading wrench, either an inexpensive beam type or a the one that you dial in and clicks when you reach the right torque. You need one that reads over 100 ft-lbs. This costs anywhere from $15 on up. No excuse not to own one really. As soon as you pickup your car from the dealer or shop when the wheels might have been off, just walk around the car and re-torque the lugs.

To be honest, I think more of the problems are root-caused by what the Stoptech paper is talking about than anything else. It seems to me that automatics "warp" more rotors than do 6-speeds.

 

Easy braking tends to cause more problems than hard braking. I beat the hell out of my original rotors for 4 seasons of Drivers Events and never had a problem with brake pulsing.
Bill

 

I have the same problem and a local dealership told me that they'd turn the rotors once for free. After that, regardless of whether the car is still under warranty, any rotor service will cost me. I almost brought the car in but decided to wait awhile until something else needs servicing. The over-torquing theory makes sense, since no other car I have ever driven developed the same problem, no matter how the break-in period was completed.

 

I agree about the A4 versis the MN6. I have 2 A4s and 1 MN6, all 98s and the A4s were always a problem within 4k to 6k miles. All new off the showroom floor. The MN6 has never been a problem. All have 3 different people driving at different times. I changed my A4 to Baer rotors & Hank pads following the bedding and break-in procedures and no more problems in over 30k miles. The wife's A4 vert I turned the rotors & replaced the pads & did the bedding procdure & no more trouble there in over 20K miles. I do the torque procedure as well. :cheers:

 

Can anyone tell me what a proper bedding and break- in of pads and rotors is?
thanks
Al

:cheers:

 

It in the link above that richin chicago listed. :cheers:

 

 

I had warped rotors, I thought. After some hard stopping for awhile it went away! Now I know why.

 

Torque of the lugnuts is a very minor issue. Cooldown after hard stops make more difference.