alvas

I am the first to have wrapped break disc?

When braking from higher speeds vibration is there. took it to audi, they put it on test and admitted that right disc is wrapped although in acceptable range. yet they ordered replacement set.

possible reason: when hot, mud/water causes part of the disc to cool too fast and if this happens not uniformely on entire disc it might wrap. this says something about qulity as well I believe.

Sia Bani

warped? Sounds like it.

alvas

thanks you are rigth- warped

Shaun

Granted, I know our brakes are very different, but premature warping has been a somewhat common problem on the A4 forum. Fortunately, it seems as though most dealers are good about replacing them. My car is on it's third set of rotors at 40K miles and I don't drive very hard.

One thing you might want to check out is the warranty policy on brakes for the S4. I think I read that the A4 warranty changed for 2004 so that Audi will <i>only cover one set of brakes under warranty</i>. In the past, there was no such clause.

Since yours wore out so soon, I'd make sure that you didn't use up your one freebie (if there is such a policy for the S4).

Hope this helps,
Shaun

Charlie_Iliff

One common cause of warped discs on A4 is overtightening, particularly in wrong sequence. A 450 ft lb gun is a bit above the 80 ft lb torque wrench recommended.
What does the S4 call for?

Shaun

Good point. I've always heard 88-90 ft-lbs for Audis.

Jet Jockey/A4 Pilot

Could it be "pad material transfer" on the disk?

DrGP

It was a persistant problem on my previous Audi A6 2.7t. Had rotors replaced at 12k miles needed to be replaced again at 22k when I turned the car in to AOA on a new lease. Be careful when using a chemical wheel cleaner. It will get onto the rotors. It can be a problem if the rotors are hot. Also the cleaner does not come in contact with the rotor in the area of the caliper thus causing the rotor to be clean everywhere other than in the area covered by the caliper and rusty or corroded in the area of the caliper. This will cause wheel shudder upon breaking that does not always rectify itself with further braking.

alvas

Good point on rusty areas.
As vibrations started after car has been outside for approx a week.

alvas

Could you just tell me more about this? thanks