Vicl

Hello, everyone!

I'm really sorry asking such stupid question! But few things are not clear to me related to the brake pads replacement.

I was reading the following links first:
http://www.audipages.com/Tech_Articl...rakestwin.html
http://www.audipages.com/Tech_Articl...tbrakesS8.html
but my Audi A8 2007 4.2 FSI has different brakes. Looking at ETKA I can see I need to pull some bolts to remove caliper. Here is the picture from ETKA


It sounds like I need to pull item #15 ... But I'm not sure how??? Also, once I'll pull it does anyone know the torque to put it back (I would assume I will need to screw it in?)

Also, I have a question about rear brakes. The link below is for the D2 rear brakes
http://www.audipages.com/Tech_Articl...earbrakes.html
but I think D3 brakes are essentially the same except electrical motor on top. The question is related to the torque as well... Can someone confirm it should be the 35 Nm for each bolt (see item #1 )?
Rear Brakes


Thanks a lot!

mishar

Remove bolts #12. They are really big and you need lots of torque to unbolt them.

Links you posted are for D2.

MP4.2+6.0

Mishar found them in the diagram--item 12 hiding there in plain sight. Item 15 are the rubber bushings and pins used by the calipers to "float" side to side in brake operation. They normally aren't touched.

As Mishar says, torque on front bolts is substantial--and in practice can be a bit challenging w/ home tools to get loose. Easier if you get under car than do it from outside the wheel well area, but have car well supported first. Torque specifics are buried in Bentley.

In practice small bolt 19 also comes off typically to deal with the brake line/ABS wire support (forget which it is), and tittle Torx bolt 8 comes out if you are pulling rotors.

Rear torque is modest; what ever the standard is for a bolt w/ an 8mm thread. I use a thin wrench to hold the threaded hole area (which forms the floating pin) from spinning; bicycle cone (bearing) wrenches in mm sizes work well. Some brake pad sets come with the rear bolts (and also sometimes the anti rattle clips); the bolts are typically coated in a Lock-Tite compound (common blue look in rear on threads only, green spray on applied to whole bolt in front), which I also apply to the threads if re using. Audi shop/dealer practice says basically replace any brake or suspension bolt that gets touched (which then skips the need for separate Lock Tite since they come pre coated now). Up to you but I usually just change if they froze up badly and/or if bolt head is getting burred a lot.

Vicl

Thanks to both of you!

As for the bolt #12 - I thought you need to remove them only when you change the discs, but not pads.

Anyway, it sounds like it is not that easy exersise anymore to replace the brake pads in front. I'll have to try it and see if I can do that

Thanks again!

mishar

Don't get scared. It is easy. Good wrench and hammer can unbolt everything. If you have pneumatic impact wrench, one that tire guys are using, even better. Just don't tight anything with it.

MP4.2+6.0

Many older Audi brakes work as you describe--basically pull some small pins (however still not the floating caliper ones) to release a spring clip and the pads. But with the D3's, you pry off the spring clip from the outside (part #4) and then unbolt the whole caliper unit. No short cut to that; I think it is part of the design of getting large calipers and rotors to tuck into relatively modest wheel sizes.

It does mean that changing the front rotors at the same time is very little extra work if you are in a marginal call on wear. As posted in some other threads recently, rule of thumb is rotors done every other brake pad change (assuming a full wear cycle) in front.

Vicl

Thanks again to both of you!
BTW, here is the link I found =>

It is for A6 2008, but look of my brakes are very close to those one. And he pulls the pins So, technically it should be easier and possible. I'll post my findings. Otherwise I'll do what Mishar suggested.

Again, no torque specs found for those bolts yet

And I agree about every other time to replace the Brake Discs. My car has 62K Km. for 6 years. In average I do 10K Km per year

So it is a first brake pad change.

mishar

If you are changing only pads it would be easier to go that way. If changing rotors too, like this guy did, than go for the big bolts directly. He also missed to grease those Alan 7 bolts/sliders.

Vicl

That's what I think as well after you scared me with those BIG bolts

MP4.2+6.0

the C5 A6 with the HP2 brakes (4.2's and early 2.7's) and D2's. The spring clips are different and quad pads feed from the outside, but the retainer pin for the caliper to the bracket that you pull for a rotor change is like that.

Yes, it should work on a D3 and I dont see any other obvious suspension stuff in the way of accessing those pins. If you go there, the pins are stainless and they are going into a cast or regular steel bracket, so definitely torque them to spec and don't way over do it.

Also from C5 experience with those similar pins, you may be tempted to grease them and they are set up as such internally as they pass through the heavy duty rubber bushings that are pressed into the caliper casting. But if you do, I would use the Audi brake grease, or at least get some that is clearly compatible long term with rubber. The critical nature of the sliding function on a floating caliper may be pretty obvious,. but more insidious is that at the inside (wheel) side of the bushing where you stick the allen socket in to loosen or tighten it has a small plastic dust cap. If the rubber swells and that dust cap ever comes out on the road, dust grit and water can enter--just like the beginning of the end when a CV boot (especially front outer) splits and is neglected. I've actually seen that specific swell on my C5 4.2 with the HP2 brake set up on one of those caps, and a few times on older Audi's with similar allen pins. Takes 100K or more miles to see it, but my Audi's have usually been on the road far longer with me and then other family. As a result, I now have a tube of the requisite Audi grease set aside for the rare use cases.