Khalizzel

Hey everyone. I'm about due for new brakes on a 2013 S8. The dealer quoted me nearly $3000 for both axels. Is there really something that different about S8 rotors and pads? Anyone done this on their own or at a private shop? Any insight would be appreciated.

MP4.2+6.0

There are no known aftermarket rotors for S8 (or any 4.0T in 400mm) in front. I think same actually for 3.0T or others at the 380mm size. Including the Adam's and various other wishful posts. It is an unusual quasi two piece rotor, probably patented and thus sole sourced. Helps with unsprung weight in meaningful way w/ large rotors. Rears are more conventional and may be other sources, but then not so expensive from dealer either. Cheapest on rotors will be get them from a discount dealer online/phone in; will cost some in shipping, but likely no sales tax either.

Pads can be had from dealer or aftermarket from suppliers like EBC and some others--for front. Again, rears are more standard parts bin stuff and easier to find.

Finally in front Audi uses some special adhesive vibration type pads at each piston--six off them per side. That adds a few hundred too. DIY'ers and indy shops can often re use them by careful removal and then sticking them back down.

The mechanical part is like many brake jobs. In rear you need VCDS to open the calipers, but that is pretty Audi standard for most any model in last five + years, and was also the case for all D3's. Do fluid flush with any brake job with correct spec fluid; these days the pretty standard low viscosity fluid for low temp ESP best operation.

BTW, do not just assume you "need" rotors, and don't let dealer bluff you. Get the actual measured rotor thickness (as worn) and compare to spec. Many dealers try to talk you into rotors at every pad change, but often you can go even other pad set as rule of thumb. Depends on driving style and exact set up though, and the wear spec is the only way to know. If pads were already done once, then yes likely it needs rotors too.

Ritz

Ouch. The rear rotors appear to be available in a number of places. The only aftermarket places I see that list the fronts appear to list a 380mm part...

https://www.europaparts.com/brake-ro...0615301aa.html

and

https://www.ecstuning.com/Audi-A8-D4...raking/Rotors/

What's the list price @ Audi for the OEM version? Are you SURE, the OEM is 400mm?

Another option, assuming there's enough thickness remaining (likely there is..a micrometer will tell the tale), is to have the original rotors machined. That USED to be common practice until the arrival of dirt cheap new rotors from China became the norm.

Best,

MP4.2+6.0

Yes, absolutely the 4.0T's--S8's and A8's--as well as W12's are 400mm. 380mm is the 3.0T size, and I think maybe the 4.2's. But not the S8 from the original post here. I own one.

On machining, I suppose, but why? Its really just cosmetics as long as the rotor face was not scratched by bare metal of a worn pad--which usually totals them anyway. Only other scenarios are true warping/runout (rare) or pad deposits (not typical w/ OE pads and can just be sanded off if need be). FWIW, from some limited M6 experience with the same kind of rotors, some shops won't (or can't) machine them because the outer ring somewhat floats on the captive pins. That means it could move laterally if the machine tools approach from one side while it is spun.

Find the prices on audiusaparts.com or various of the other discount dealer sites. Same with the adhesive shims if you decide to replace--besides the pads that is. You also need a sensor if you have worn through one to where light is on. List on the rotor is something like $320 (EACH) I think and discounted is around $260. Adhesive shims are something like $260 list for the set (12) and a little under $200 discounted. As I mentioned others are reporting being able to reuse those if careful. If you order, I would definitely call these in and not just do it online--too much confusion about the sizes is out there and faulty web pages and all. A dealer will do it by VIN and then any risk of wrong parts # is on them. The shipping will add up some on rotors too, so you can know what that is going in.

Ritz

To avoid the noise/squeal during the time that it takes the new pads to wear in to the existing grooves. And the OCD side of me just likes having that mirror smooth finish for the pads to break-in on.

Best,

MP4.2+6.0

FWIW I really don't extra noise on my used rotors. The wear lines/grooves are lateral anyway. Sure I have refinished the normal cast iron ones on occasion, but these are an unusual design. Most commonly I use EBC red pads (and occasionally stock). EBC's have a break in compound applied right to them. Sort of looks like medium fine sandpaper actually. No real noise for me on that either beyond first stop hardly different than if I washed car and let it sit a day or two. I take a 30 minute spin or so to bed them, check brake function in general, etc. post work and bleeding. Have a set off EBC's on hand for the S8 fronts; took a while to get when they were on backorder/pending manufacture. One of the few non dealer choices for front in the 400mm's.

Ritz

The ancestral family business was a gas station and repair shop that was opened by my grandfather in the 30's and remained in business until my father retired around the turn of the century. Working there as a kid, in high school and on/off while I went to college, I probably milled 1000-ish rotors. That's what we did back then. Unless the original was grossly out of spec it got milled and re-used. It's not just the grooves on the wear surface, but the inevitable raised rusty lip around the circumference that tends to make noise. Call me crazy, but I just like it milled flat and don't feel comfy just plopping a new set of pads on the old rotors without that step.

Best,

audionlineparts

I can definitely supply you with everything you need for this! (except VCDS) and save you on the shipping because all AudiWorld customers get free shipping. (promo code "AUDIWORLD") If you wanna shoot me your VIN i can get you all the part numbers for you to order on the site or at least find the right things somewhere. Let me know what we can set up! I probably have everything in stock and can ship out today! Let me know!

Thank you!

Ritz

Are you part of Audi Meadowlands or Town Audi in Englewood? I am in that area fairly often so it would be nice to order parts online when I know I'm going to be in the area and then drop by to pick-up on the way home.

Best,

audionlineparts

Audi Meadowlands! Over in North Bergen. Just let me know what you need and ill have it ready for you when you need it!