# HELP! Issue with ongoing brake rotor warping on my B7 Audi A4



## awagner06 (Mar 15, 2005)

Hi all!

I have posted this same thread across several of the Audi forums in hopes that someone out there has some insight on the very strange, ongoing brake issue I have been experiencing with my 2007 B7 A4 S-Line.

Two years ago I slid (on black ice) wheel first into a curb at maybe 5 MPH. At the time the steering wheel was turned 2/3 of the way to the left, and the passenger side front wheel collided with the curb. After hitting the curb, the car incredibly drove just as it always had - straight, no wheel shake, no pulling to one side, no effect on braking.

Fast forward a few months and I noticed that I started to have some steering wheel shake each time I applied the brakes. The issue became more pronounced and I decided to replace the front pads and rotors. Prior to this, the car had the original pads/rotors on it with ~90K miles. After the replacement, the car was back to 100% smooth braking. After the replacement I did a 2,000 mile round trip through New England and back home in Virginia. During the trip (of mostly highway driving), I noticed that the steering wheel shake returned while braking. After taking the car back into my very reliable local Euro car shop, I was told that the front right rotor was warped again.

Since that time, the shop has done an alignment, aligned the sub frame, replaced the front calibers, checked the wheel hub and bearings, and have even tried driving the car at highway speed and then stopping to immediately check the rotor temps with a heat gun - which yields uniform temps all around. I have had a total of 5 sets of brake pads, 3 sets of rotors, and the new set of calibers put on the car. Each time, the car is smooth for ~2,000 miles or so, then the front right rotor is warped again. I have noticed that there is a bit more brake dust that forms on the wheel in question then on the drivers side, but thru touching the wheel, it never feels warmer than the drivers side, after a longer drive.

Any insight/suggestions/thoughts that anyone can provide would be greatly appreciated. I absolutely love the car, and it has been incredibly reliable since I purchased new. The lack of smooth braking definitely takes away from the enjoyment of driving though!


----------



## petethepug (May 25, 2001)

You've got a caliper piston that's stuck, the rotors installed out-of-true with the hub or rim not torqued to spec on the hub. Keep in mind the rotors don't warp. It's uneven wear. So many have gotten used to hearing warped rotors it's assumed those cast iron brutes could be pressed out of shape from heat or pressure.


----------



## [email protected] (Jun 20, 2014)

Yeah, it's very likely just pad deposits/uneven wear as stated above. It's incredibly rare to actually warp a rotor even on track, so the chances of that happening on the street are practically zero.

I'd get that front suspension checked for damage, and if you still have the old rotors, you might very well be able to use them after ridding them of the deposits.


----------



## Chickenman35 (Jul 28, 2006)

What brand rotors were put on the car and what brand pads? Have you tried different brands of pads?

Some pads are really bad for uneven deposit buildup. I've had a couple of bad experiences with Stop Tech pads ( High Performance division of Centric ). Euro made semi metallic pads are usually very good ( ATE, Brembo, Ferodo Valeo ). Bendix Titanium II pads are very good. Akebono Premium Ceramic pads are very, very good... however MOST " Ceramic Pads " are cheap marketing schemes. Beware of what you buy. 

The replacement rotors may be of an inferior off shore brand, Quality varies a lot with rotors. Some are absolute junk. Some of the worst offenders are " Fan Boy " rotors with slots or holes. P***r-Slot comes to mind. Brembo, ATE, Ferodo, Valeo, Zimmerman, Bendix, Raybesto's, Wagner and of course OEM are all good brands. 

Brake shop may be installing inferior products. Of course they'll never admit that. " House brands " are often sketchy quality.

More dust on right front wheel is suspicious. Since calipers have been replaced, a sticking caliper is unlikely...but not impossible. You may have bent a hub spindle from contact with the curb...but that should have shown up when you got the alignment. Unless the Tech missed the info. Kingpin inclination and Camber would have been out of spec.

Edit: Improper wheel torquing can also cause brake shudder as mentioned above. If you see the Tech banging the wheel on with an Impact gun, walk out and never return to that shop. A Torque wrench should always be used and wheels torqued to the proper value.


----------

