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At 124K miles, you probably do have bushing issues unless they were already done, and even then only if dealer or OE level parts. I went through two OE sets by those miles on my D3. OES on D3 was Lemfoerder. Probably still true for D4. On D3 even dealer sold bushings separately, which were marked as Lemfoerder. Having just looked, they aren't broken out on the D4 ETKA parts diagram though, so may not be available. RM European currently has D4 Lemforder upper arms in $80 range, each. Takes 4 separate ones in total. A very good price for OE/OES. If you can find bushings, you then need a press to install them, or need to find a machine shop or mechanic to do it. (Meyle is junk BTW as far as I'm concerned, if you look at their site).
Given your miles, I would be replacing upper control arms before rotors, unless repair history says arms/bushings were done in last 50K miles. You can also unbolt the upper pinch bolt that holds them in on ball joint side and then do a careful inspection. Hard to get a true sense when they are bolted fully in place, but the deep cracks become obvious when you can move them around from tie rod end. If yours are literally torn out, that is the final stage of complete failure and then easy to see. Lots of creaking in suspension is another sign, plus the front inner tire wear. If you do control arms, also do sway bar end links. Known wear issue, even more so on D4 and in some cases by 50K. D3 got closer to 100K on those. Still do rotors of course if they are worn below min spec.--at your miles absent extraordinary non stop highway driving, they probably have already been replaced at least once before. Control arm job typically leads to an alignment BTW, especially if one was done in recent timeframe on worn bushings.
...you probably need to be taking off a wheel for more inspection given the various items...
I think I'll probably just take it to my local shop and have him look at it, he can probably diagnose it in a quick glance. Audi sourced arms are $250 for both uppers on one side, which isn't horrible. I'll update when I get some more info.
Full disclosure, the other symptom I'm having is the brakes creak like crazy when letting off from a stop, and also just before coming to a complete stop. I don't think rotor warping would cause this?
Last edited by sushistrip; 10-09-2018 at 12:11 PM.
Full disclosure, the other symptom I'm having is the brakes creak like crazy when letting off from a stop, and also just before coming to a complete stop. I don't think rotor warping would cause this?
The creaking can be pads near end of life--pistons moved way out so things move around more. BUT, those noises are also classic sway bar end link and upper control arm stuff. Parts are loading and unloading force wise in those scenarios, and road and wind noise drops to zero so you hear things more. For both end links and upper control arms, in my experience it is "WHEN not IF" on both D3 and D4. Suspension was designed for mid 90's A4 essentially (other than air ride). They have beefed up parts a somewhat over the generations, but not nearly as much as the wheel, brake and overall car weight/pork have all gone up. At 125K it is a very good bet time is up, as it were.
So, yes you do have the "simpler" ones from what I can make out in picture. Same basically as the D3 set up was--twin pistons on one side only, with a semi floating caliper. Thus the alldatadiy picture was NOT yours. That set up is the Brembo's, like on S8 or S7.
What that means in turn is you can do pads only by only pulling calipers at the sliding pin. Those are allen head, 7 or 8 mm IIRC from my other Audi and VW experience. If you do rotors, you have to pull the caliper bracket (separate part) from the hub. Just to tie something off from earlier in the thread, you only need the pricy anti vibration shim set if you have the Brembo calipers like on S8. On yours, the caliper pad retaining clip that you sort of see on the side of the caliper serves the same purpose in theory, plus the bushings I mention in #2 below. Three illustrations below are:
1. Page from the "real" manual showing that set up. If you look at the caliper bracket shown as part #23 in the first picture, you see those "ears" at the two ends. Those wrap around the rotor and are why it has to be removed to get rotor off. I think one of those "ears" is the dark area in your lower picture.
2. The ETKA parts page for same ones. The allen pin you pull to get caliper off the bracket is #3. Or, #14 if looking at the manual page. You don't replace those unless worn--stainless steel. At 120K miles on my D3 they still showed no obvious wear. BUT, given you mentioned the noises right near stopping, another guess is your bushings that surround those pins are worn. I found that on my D3. You can replace them by hand just by working them with a screwdriver. Part #16. $40 list from Audi for each set (x2), but only $10 for the jobber ones from rock auto. See next item/picture. Bolts you do replace if you pull caliper bracket are #13 here in ETKA diagram (qty 4 total). Same as bolt #5 in shop manual page, which shows the torque. The little torx screw that hold rotor is #10 on this ETKA parts page. One for each rotor you pull. Notice BTW this diagram also shows your rotors at 380mm (part 9), which I think ties off to the A8 4.0T.
3. rock auto page with the #16 equivalent--the Raybestos one.
Okay, I'm on the same page with you now. I had clicked on the wrong diagram in alldata. The one I'm looking at now matches what you posted. Also no shims on the brake pads for my car. Alldata calls for tool T50036 to remove the guide pins, which looks to be just a plain long 9mm hex socket. Just for reference, do you think it's easier to pull the caliper bracket with the caliper still attached? If I'm going to be changing pads and have to pull the guide pins anyway, I wonder which should i do first.
Last edited by sushistrip; 10-09-2018 at 06:29 PM.
Okay, I'm on the same page with you now. I had clicked on the wrong diagram in alldata. The one I'm looking at now matches what you posted. Also no shims on the brake pads for my car. Alldata calls for tool T50036 to remove the guide pins, which looks to be just a plain long 9mm hex socket. Just for reference, do you think it's easier to pull the caliper bracket with the caliper still attached?
On your question, definitely pull them separately. The caliper part is easy. Just undo those allen head pins, undo the pad wear sensor, pry open the pads (pistons) a bit to clear the rotor wear lip as you pull the caliper outward, and have a tie strap or piece of wire at the ready to hang the caliper from. With caliper loose, that is when pads come out. Use the piston side one first with a C clamp to squeeze pistons al the way back in. And with caliper loose, lots of room to get at that bracket to remove and replace. You also want to clean and grease the slide points where caliper meets the bracket, plus at 120K+ replace the rubber bushings discussed in prior reply.
On your question, definitely pull them separately. The caliper part is easy. Just undo those allen head pins, undo the pad wear sensor, pry open the pads (pistons) a bit to clear the rotor wear lip as you pull the caliper outward, and have a tie strap or piece of wire at the ready to hang the caliper from. With caliper loose, that is when pads come out. Use the piston side one first with a C clamp to squeeze pistons al the way back in. And with caliper loose, lots of room to get at that bracket to remove and replace. You also want to clean and grease the slide points where caliper meets the bracket, plus at 120K+ replace the rubber bushings discussed in prior reply.
At the risk of being Captain Obvious, from the above parts diagram, the front rotor diameter for the 2015 A8 4.0T is 380mm? If so that's helpful to know when I get the front brakes done next year. There was some confusion on the rear brake diameter with the indy shop that did mine - their parts wholesaler and the Audi parts site both showed 3 different rear rotor sizes. Ultimately I called the dealer parts desk and was told 356mm. There was a post here in one of the D4 brake threads that implied that the front rotors are always 400mm if the engine is 4.0T, so I'm just looking to clarify.
On your question, definitely pull them separately. The caliper part is easy. Just undo those allen head pins, undo the pad wear sensor, pry open the pads (pistons) a bit to clear the rotor wear lip as you pull the caliper outward, and have a tie strap or piece of wire at the ready to hang the caliper from. With caliper loose, that is when pads come out. Use the piston side one first with a C clamp to squeeze pistons al the way back in. And with caliper loose, lots of room to get at that bracket to remove and replace. You also want to clean and grease the slide points where caliper meets the bracket, plus at 120K+ replace the rubber bushings discussed in prior reply.
Cool cool. I appreciate all the advice, I'll be saving hundreds on labor doing this myself as opposed to the dealership, possibly thousands. I'm having a local shop inspect my bushings next week, so I'll update after that happens.
Cool cool. I appreciate all the advice, I'll be saving hundreds on labor doing this myself as opposed to the dealership, possibly thousands. I'm having a local shop inspect my bushings next week, so I'll update after that happens.
Yes, big $$ savings--even if you use all OE/dealer parts but simply buy them via one of the on line discounted dealers. Front rotors for D4 are essentially dealer only in the various common sizes because of their design. Brake work is probably the single highest margin service business dealerships do, and that margin is extra money from your pocket. Posts talking about $2K front brake and rotor jobs on the board are not uncommon--which to me is ridiculous.
10-09-2018, 12:00 PM
