anotheraudiowner

Hello everyone, I got an odd problem for you guys, when I purchased my A8 it had a slight shaking in the front when pressing the brakes, so I purchased a set of new brake pads only(was leaving for a road trip that evening and nobody had rotors in stock) the shaking became WAY less, so I was happy for the time being

while replacing the pads I noticed both sides upper control arms bushings were getting to the end of their life, torn and leaking, I figured that had to do with some of the shaking as well, and the lower sway bar links were also shot, so I ordered 4 new upper control arms, and the sway bar links, 4 months later when I finally had the time to replace them, I installed all the control arms and the links, shaking became even less but was still there, so I decided I'll take the rotors off and have them resurfaced before buying new ones, $15 a piece vs $90+, so that was yesterday, I installed the rotors and now the car shakes like a **** when pressing the brakes! More then it did when I first bought the car

so my question is, did the brake pads get ruined running them on the old rotors or is there something else that would cause this?

Also, are the rotors supposed to have the little bolts holding them onto the wheel hub? All my previous cars did, but on my A8 they just sit there loosely and get tightened when the wheel is installed, that seemed really odd to me, is that my shaking issue?

Really want to get this figured out as i dont even want to drive the car right now, it only shakes when applying the brakes vigorously, if your just cruising along and slowly press them it's almost not even there, it just seems like something is loose, I came back home and double checked everything after the test drive, everything is tight like it should be

richard-tx

Sway bar is what I would look at next.

The bolts that hold the rotors to the hub are supposed to be tight before mounting the wheels. What is more important is that all rust on the hub be removed before installing the rotors.

anotheraudiowner

What would be wrong with the sway bar if I already replaced the sway bar end links?

in the picture attached, NOT AN AUDI A8 rotor, but I'm talking about having the bolt his socket is on, do the a8's not have that?

richard-tx

The sway bar bushings is what I would suspect. The are bonded or molded right to the sway bar and they do fail. The solution is to replace the sway bar.

anotheraudiowner

Would it only shake when pressing the brakes though? I'll definitely check them, but wouldn't the car shake all the time if they were the culprit?

ltooz_a6_a8_q7

Did you check the rotors for flatness before putting them back in. The resurfacing machine may not be totally straight? Check to see if the hub don't have any kinks, debris of some kind.
Vibration must cause by the uneven rotors, tires or pads while braking imo.
Cheers,
Louis

anotheraudiowner

Sadly I did not think of checking for evenness didn't think about that, I'll have to take them off and set them on a glass surface to see, I'm thinking it's rotors because it barely shook before I got them resurfaced, that was just my final piece to the puzzle, or so I thought, to completely get rid of the shaking

i will double check them and hopefully I get an answer, I don't mind buying new, but I figured I'd give these a shot first, so now I'm $30~ into rotors booo! Haha

ltooz_a6_a8_q7

I did turn the rotors before on my D2, it didn't look so good, but it didn't vibrate.
2 front Turned rotors.

TSHong

Just replace you rotors. Turning them just made them thinner so you are back to square 1.

richard-tx

Brembo rotors are not expensive. You can get them from Amazon.