Brake Rotor and Pad Replacement A8
#1
Brake Rotor and Pad Replacement A8
OK...I can't see myself giving the dealer $1200 for pad and rotor replacement. Question, is the rotor and pad replacement on the D3 A8 any different from any normal vehicle? Will I need any special tools or a VAG-COM for anything. I'm starting to look for prices on pads, and rotors now. Anything else I'm gonna need?
#2
AudiWorld Super User
OK...I can't see myself giving the dealer $1200 for pad and rotor replacement. Question, is the rotor and pad replacement on the D3 A8 any different from any normal vehicle? Will I need any special tools or a VAG-COM for anything. I'm starting to look for prices on pads, and rotors now. Anything else I'm gonna need?
No special hand tools required. The front calipres are simple push-in pistons IIRC. I bought a Harbor Freight junk caliper compression tool that I used but I think a C-Clamp and old pad would have worked just as well. Or, if no C-Clamp, simply prying the caliper open before unbolting it from the carrier would have been fine on the fronts.
#3
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How about it $1200 for a brake job? For that $ you should get another "job." But I digress....
Changing brakes on these cars is the same as you're probably used to. In the front, anyway. The rear requires a VAG COM to release the parking brake. That's why the dealer needs you to come back in. If you can make friends with an Audi Mechanic, he may be able to do it for you on the slide, er.....side....
Changing brakes on these cars is the same as you're probably used to. In the front, anyway. The rear requires a VAG COM to release the parking brake. That's why the dealer needs you to come back in. If you can make friends with an Audi Mechanic, he may be able to do it for you on the slide, er.....side....
#5
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What I would do personally. Is buy all the original OEM rotors and brakepads. I think they use them for a reason, they have good bite and long life. Regardless buy your own parts do the front on your own, it is simple. And just have the dealer or indy shop do the rear because you need a vag com to release the piece on the rear set.
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I don't know about IRotors but I agree with Brozee on the stock rotors. I do, however, think EBC makes a better pad. I now have the yellows on mine and though they dust a little, they bite WELL! You could try the Reds as they are ceramic and will dust little but will bite better than stock. I have a friend who just installed the greens and likes them quite a bit as well.
Red -- like stock, but better, low dust
Green -- better bite, maybe a little more dust?
Yellow -- Race pad, BITES! cold or hot, great performance
Red -- like stock, but better, low dust
Green -- better bite, maybe a little more dust?
Yellow -- Race pad, BITES! cold or hot, great performance
#7
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But, out of the EBC pads do they match the lifetime of the OEM pads, this is what I was wondering. I know the ceramic would probably eat up the rotor faster but what about the others?
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#8
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Ceramic pads do usually eat up rotors faster however, I had some Bendix ones on a Chevy Impala once that lasted a LONG time and were easy on my rotors.
#10
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Actual experience; lots of details/info.
I have been running EBC reds for about 25,000 miles now. Car has about 50,000 miles now. I spent about 8,000 miles on OEM pads before I changed them on my CPO w/12 I bought with 16K miles then on it. At the time I did the brake work the dealer noted wear on pads during an annual service and suggested a pad change (in rear I think) was in order, but I said I would wait. That is when I did the change to the drilled and slotted OEM rotors and paint refinish on the calipers (in my auto sig links), coupled with EBC red pads.
My car is a W12 with bigger front rotors than a 4.2 (385 mm vs 360 mm on many). Same as an S8, other than the S8 retainer trim which has no functional difference. W12 (or S8) front uses pads that are essentially identical to a 4.2, with pad material shifted in the millimeter range inward for the W12 (S8). That trivia might seem counterintuitive, but the bigger rotor was fundamentally accomodated either in the caliper or the hub bolt up point by moving it out from axle center about half an inch. In EBC's, they don't even bother with that millimeter or so shift; effective swept area is a bit higher with the 4.2 pads from my calculations when used in a W12/S8, and it has the practical effect of almost eliminating the outer rotor wear lip. This is all to say even w/ bigger rotors, the W12 is a relevant comparison to the 4.2 since the pads are pretty much the same. W12 might be expected to have more wear given the 500 pounds or so difference (L body to L body), and the general go fast nature of the car.
On the rears, the set up is different in all of rotors, pads and calipers. Same as old C5 RS6, and again same as current S6 and S8. Maybe same as current S5 too from one I looked at briefly. But when you get down to the pad, it is relatively small compared to the fronts--arguably more so than most front to rear Audi pad comparisons I have made across C1's, C3's, C4's and C5's.
For actual experience, net, wear is similar from OEM to EBC; might be a bit better in EBC's favor. My front pads look to be just about 50% worn, which would suggest they might run to around 40,000 miles before the light comes on. My driving is strong majority suburban and local stop and go, with some highway. Also, since my rotors are now slotted, if anything I would expect that would have increased pad wear rate a bit.
I just changed my rears this week, which were at an indicated 3mm remaining visually, and the same thing I found on VAG COM actually when I reset the electronic brake and rear pad wear settings. From my notes I can see I put 26,000 miles on those pads in about 26 months. That would put their full life at just over 35,000 miles down to the backplate, and maybe 30K miles with a safety margin or when the wear light would kick in anyway. Close to the OEM rears which I pulled at 23,600 miles with some life still left but similar caution from dealer at the time. Notice on my car, I am actually seeing a rear wear rate for miles driven at or above the front rate. Have never had that on an Audi before! On all my prior C body (A6 and predecessors) I usually ran two front pad changes for every rear change (or even more lopsided on older FWD only ones). I attribute it to: 1) This car has really big front brakes! And really big front pads, which are shared with the later 4.2's. 2) Given weight and performance of the car, rears may actually have to work more as it gets near front braking limits; I know from having run 255's instead of 275s at one point I was more likely to kick in the ABS briefly in faster driving 3) the front has been sized up so much, the rear pads are left puny by comparison.
On pad material--having acquired a new set of OEM front pads and the EBC pads, actually the OEM pads seem much rougher. Hard to be sure on EBC's since they have the break in material as a coating; having seen them worn though I think they are not as rough a pad as the OEM's. In particular, the OEM's look like a semi metallic. Course chunks of metal looking material are obvious; courser than I have seen in other pads, save maybe very heavy American body on frame type stuff. Likely reflects generally large pad and rotor size. To me that material translates most likely to good general performance, more rotor wear, and a good amount of dust. As a comparison, the OEM pads look most like a MetalMaster/Axxis/Repco semimetallic pad I have used in the past on older (pre-ABS) Audi's where I was less concerned w/ brake dust and wanted more stopping power out of a more modest brake set up. The OEM pads I mention are the W12/S8 variant, so I suppose the 4.2 pads could use a different and maybe less aggressive material.
On rotors, wear also looks similar so far. I had my OEM rotors refinished after I pulled them for future use or if I resell and want full OEM look back. Against the wear limit spec for the fronts (3mm as I recall for the 385's), I could project about a 90K rotor life to min. spec. Rears were less worn, but spec is less too since they aren't as thick to start. Net, that is pretty good rotor life, and really beyond what a lot of posters are saying their dealers are telling them about rotor replacement at much lower mileage.
My car is a W12 with bigger front rotors than a 4.2 (385 mm vs 360 mm on many). Same as an S8, other than the S8 retainer trim which has no functional difference. W12 (or S8) front uses pads that are essentially identical to a 4.2, with pad material shifted in the millimeter range inward for the W12 (S8). That trivia might seem counterintuitive, but the bigger rotor was fundamentally accomodated either in the caliper or the hub bolt up point by moving it out from axle center about half an inch. In EBC's, they don't even bother with that millimeter or so shift; effective swept area is a bit higher with the 4.2 pads from my calculations when used in a W12/S8, and it has the practical effect of almost eliminating the outer rotor wear lip. This is all to say even w/ bigger rotors, the W12 is a relevant comparison to the 4.2 since the pads are pretty much the same. W12 might be expected to have more wear given the 500 pounds or so difference (L body to L body), and the general go fast nature of the car.
On the rears, the set up is different in all of rotors, pads and calipers. Same as old C5 RS6, and again same as current S6 and S8. Maybe same as current S5 too from one I looked at briefly. But when you get down to the pad, it is relatively small compared to the fronts--arguably more so than most front to rear Audi pad comparisons I have made across C1's, C3's, C4's and C5's.
For actual experience, net, wear is similar from OEM to EBC; might be a bit better in EBC's favor. My front pads look to be just about 50% worn, which would suggest they might run to around 40,000 miles before the light comes on. My driving is strong majority suburban and local stop and go, with some highway. Also, since my rotors are now slotted, if anything I would expect that would have increased pad wear rate a bit.
I just changed my rears this week, which were at an indicated 3mm remaining visually, and the same thing I found on VAG COM actually when I reset the electronic brake and rear pad wear settings. From my notes I can see I put 26,000 miles on those pads in about 26 months. That would put their full life at just over 35,000 miles down to the backplate, and maybe 30K miles with a safety margin or when the wear light would kick in anyway. Close to the OEM rears which I pulled at 23,600 miles with some life still left but similar caution from dealer at the time. Notice on my car, I am actually seeing a rear wear rate for miles driven at or above the front rate. Have never had that on an Audi before! On all my prior C body (A6 and predecessors) I usually ran two front pad changes for every rear change (or even more lopsided on older FWD only ones). I attribute it to: 1) This car has really big front brakes! And really big front pads, which are shared with the later 4.2's. 2) Given weight and performance of the car, rears may actually have to work more as it gets near front braking limits; I know from having run 255's instead of 275s at one point I was more likely to kick in the ABS briefly in faster driving 3) the front has been sized up so much, the rear pads are left puny by comparison.
On pad material--having acquired a new set of OEM front pads and the EBC pads, actually the OEM pads seem much rougher. Hard to be sure on EBC's since they have the break in material as a coating; having seen them worn though I think they are not as rough a pad as the OEM's. In particular, the OEM's look like a semi metallic. Course chunks of metal looking material are obvious; courser than I have seen in other pads, save maybe very heavy American body on frame type stuff. Likely reflects generally large pad and rotor size. To me that material translates most likely to good general performance, more rotor wear, and a good amount of dust. As a comparison, the OEM pads look most like a MetalMaster/Axxis/Repco semimetallic pad I have used in the past on older (pre-ABS) Audi's where I was less concerned w/ brake dust and wanted more stopping power out of a more modest brake set up. The OEM pads I mention are the W12/S8 variant, so I suppose the 4.2 pads could use a different and maybe less aggressive material.
On rotors, wear also looks similar so far. I had my OEM rotors refinished after I pulled them for future use or if I resell and want full OEM look back. Against the wear limit spec for the fronts (3mm as I recall for the 385's), I could project about a 90K rotor life to min. spec. Rears were less worn, but spec is less too since they aren't as thick to start. Net, that is pretty good rotor life, and really beyond what a lot of posters are saying their dealers are telling them about rotor replacement at much lower mileage.
Last edited by MP4.2+6.0; 05-15-2010 at 11:45 AM.