LenVOS8

<center><img src="http://pictureposter.audiworld.com/47332/1036115379258_s8gal3.jpg"></center><p>I am relatively new to my 2001 S8 - bought it pre-owned (via EBay) in Mid Novmeber and have put about 750 mile on it since.

My Brakes have a very shrill screech when coming to a stop particularly when backing up, but also happens at slow speeds when braking going forward. I looked at the front pads and they seem to have a fair amount of life left and not getting any warning on low pad via the diagnostics of the car. Any Thoughts?

Problem two - Noticed today that the trunk release button in the front driver door frame was sticking very far out - it turns out that the little plastic clip inside the button broke off - I guess my ony choice is a visit to the local audi parts department for a new one. Has this happened to anyone else here, any way to avoid in the future.

ryoung

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"AS15565" reported the same problem a few months ago in this x-post. Check the replies to his post for some suggestions.

I don't believe brake squeal with the S8 is a common problem. As much as anything else, I suspect it depends on driving (braking) style and the luck of the draw on pad frame dimensions and exactly how the pad fits into the caliper. I've never had the problem with my S8, either with the original Brembo's and OE Audi pads or the Alcon's with Ferodo DS2500 or Pagid RS4-2 Blue pads.

And congratulations: I think you have the misfortune to be the first to report a problem with the trunk release button.<ul><li><a href="https://forums.audiworld.com/a8/msgs/13223.phtml">S8 brake squeal</a></li></ul>

rmw18k

The brakes on my S8 are so loud they wake up the neighbors when I back up. The dealer is going to replace the pads and see if that helps. I would doubt it though as it is a common problem. I am looking for some semi-metallics like Repco but haven't found any yet that will fit the S8. If anyone knows of some I would like to know.

ryoung

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The Pagid and Ferodo street pads are both semi-metallic and available for the S8 front &amp; rear (and also for my front Alcon calipers).

I'm currently using the Ferodo DS2500 "H" compound street pad. No complaints at all. The rear pads come with the anti-rattle spring installed in the frame and include a new set of the bolts that you remove to change the pads.

The <A HREF="http://www.cobaltfriction.com/prod-cat/brake_pads_ferodo.htm">Ferodo Compounds</a> are available from <A HREF="http://www.cobaltfriction.com/">Cobalt Friction</a>. I'm been very impressed with their very knowledgeable and first class service. For a track only pad, I'd recommend the DS3000 "R" compound.

Never satisfied, though, once the Ferodo's are worn out, I plan to try the Pagid RS 4-2-1 Black street compound. Last year I attempted to use the Pagid RS 4-2 Blue as both a street and track pad -- it was fine on the street in the Summer, but it literally melted on the track. Since the 4-2 Blue is race pad, I wouldn't recommend it for the street where you get cold weather. The only "problem" with a Pagid pad is that the rears don't have the anti-rattle spring installed in the frame. It's no big deal, but you need to pry the springs out of the old pad frame and reuse them on the Pagid. The rear pads don't come with new caliper bolts either, and you'll have to reuse these also.

The <A HREF="http://www.pagidusa.com/characteri.html">Pagid Compounds</a> are available from <A HREF="http://www.stasisengineering.com/">Stasis Engineering</a>. For a track only pad for our heavy cars, I'd recommend the RS 14 Black, which is a ceramic composition rather than a semi-metallic pad. This very interesting chart shows <A HREF="http://pictureposter.audiworld.com/17157/pagidcompounds.jpg">Coefficient of Friction vs Temperature</a> for four of the Pagid compounds.

As I mentioned earlier, I've never had a squealing problem with any Ferodo, Pagid, OE Audi pad as-is; but you might want to take a file and bevel the trailing edge of the pad to reduce the likelyhood of squealing in reverse.

Good Luck,

PaulW

I recently switched my front brakes from a Porterfield compound to stock compound. My squealing is essentially gone. Sounds like yours in reverse is pretty noticable.

After years of doing my own brakes and shopping the parts on price alone, I realize that compound is something that should be considered (as Randy's post lays out very well).

For those who don't know (which includes me) about compounds, here's what I've found.

<b>Soft Compounds</b>
You can get soft compounds (stock pads) that are more like a pencil eraser pushing against the rotor. It creates dust relatively easy, they are quiet, and work well when cold or in the cold weather. If you bring them to a track, or run them coming down a mountain with a large load on them they get too hot, and they loose their effectiveness.

<b>Hard Compounds</b>
You can get hard compounds (Porterfields, or any of the track compounds Randy mentioned) that are more like a metallic compound pushing aginst the rotor. They prouduce less dust, but have a hardness closer to the rotor hardness, so the rotor wears more. They can also cause the rotor to resonant. My Porterfield's resonated the rotors something fierce! Mostly under regular braking. If I was to brake really hard, then it wouldn't.

To compound the problem (no pun intended), I used stock compound (soft) on the rears, with Porterfields (hard) on the front. Therefore, the brake pressure required to get the Porterfields working is different than stock. So there is a lot of dust on the rear wheels because they are operating at higher than normal pressure (or at least that's what I think).

<b>Moral to the Story</b>
There seems to be a lot more to brake compounds than meets the eye. When I do my brake upgrade, I will have a set of Porsche stock pads for the front matched with Audi stock pads on the rear. These will be used for the street.

When I go to Mid Ohio, I will get a set of high temperature compound pads for both front and rear, once again, to match compounds and so they won't melt.

From my understanding, there will be relatively low brake wear with both of these set ups for their intended applications. It's cheaper to have two sets of pads, and they work better too.


Don't know if this helps an '02 from stopping to squeal when in reverse, but thought it might be helpful to some.

pw

TKG 26

according to my Audi dealer, there is no cure....

they've replaced all 4 pads and rotors with new ones, and the problem still persists - they said to live with it....besides, it doesn't really bother me (other than being embarrasing)

i drive my car somewhat aggressively, but i don't beat on it - well, maybe sometimes

my threshold/panic braking is and has always been smooth (i.e. no vibrations/shuddering from the brakes).

PaulW

Man, that color is cool.....switches color from day to night I bet....

LenVOS8

Thanks for the compliment - yes in different light it looks different colors - Its very different especially from all the Black S8's that I see.

As for the brake pads - I think they may have been glazed - following ryoungs linked posting I tryed a few hard stops from 70 - 0 on Saturday and that seems to have reduced the problem.

ryoung

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the next time you replace the rotors, you might want to consider having them slotted. You can have this done to the original S8 rotors, and it seems to do a good of keeping the pads clean and preventing a glaze build-up with "normal" driving. To prevent the slots from causing localized stress where cracks could initiate, the slots should have a radiused bottom and not extend all the way to the edge of the rotor.

<img src="http://pictureposter.audiworld.com/17157/alcon_s8.jpg">