Rumbling RS4 brakes..?

[Desmo]

My standard RS4 brake set up (non-drilled disks) has developed a rumbling, grinding sound when braking hard from 100mph, no weight in the car, or from 70mph when braking hard with passengers/weight on board, with slightly increased braking distances. Under normal braking everything feels just fine. Its definitely not the ABS cutting in. Having had the car serviced by a reputable main dealer a couple of months ago (major 60k), they confirmed the brakes/pads were fine, so I'm at a loss. Can anyone tell me if this sounds like new disks or calipers required? I'd like to do the RS6 caliper upgrade, but now not sure if I need to include disks? If both, roughly what can I expect to pay?

[CliveH]

Sounds like worn pads/discs, but you say that's been checked.

As regards the RS6 upgrade, you can pick the calipers up for about £650. They will mate with your stock RS4 discs (360mm) or you can use the RS6/RS6+ or RS4 B7 discs (all 365mm), but you would need a different caliper mounting bracket if you go for RS6/RS6+ due to the different offset of these discs.

In case you're wondering, the difference between RS6 and RS6+ discs is that the + discs are "cross-drilled" (cast).

[Brooner]

I had the same problem down to worn disks if both dicks and pads worn i would definatly recomend the RS6 caliper upgrade if you buy it all on line you will only the extra cost of the calipers and for me that was a no brainer here's a link with costs for my upgrade http://www.rs246.com/index.php?name=PNp ... ic&t=53686

[Doug_S2]

Stock b5 rs4 discs are not great discs! I think it is a waste of time putting the 8 pots on those discs.

The B7 RS4 setup costs are around £1180 (depending where you get them) + fitting.

RS6+ discs require custom brackets and a small modification to the strut so cost more.

[Desmo]

Folks thanks for the advice. I can't imagine my problem can be anything else but disks/pads, but I'm just surprised that the dealer, a London based main dealer, who I went too as they were recommended on this forum, checked the brakes after my specific request and found nothing. The problem has only gotten worse. It looks like the B7 RS4 disks with RS6 calipers seem the way to go, but has anyone got an experience of the difference between the stock B7 RS4 disk/caliper set up and B7 disks+RS6 calipers?

[Desmo]

[quote="Brooner"]I had the same problem down to worn disks if both dicks and pads worn i would definatly recomend the RS6 caliper upgrade if you buy it all on line you will only the extra cost of the calipers and for me that was a no brainer here's a link with costs for my upgrade http://www.rs246.com/index.php?name=PNp ... 3686/quote]

ps) Brooner, your previous posting listing parts and gives a price of £2700 for supply/fit - was that for front & rear?

[CliveH]

Desmo,

The RS6 and RS4 B7 front calipers are identical in all respects, other than the RS6 calipers have an additional strut.

Yes, Brooner's price was for front & rear.

[Brooner]

yes total for front and rear as Clive said would recomend the B7 disks as there a stright bolt on

[Desmo]

Clive / Brooner - thanks. I'll order the parts online. Can any of you recommend a quality outfit to do the fitting for me - Star Performance is Scotland, a bit far I'm in London (nr City). Will go anywhere within reason (M25). Looks like I'll be looking for another service dealer as well. Not impressed by the last three !

[Brooner]

Any trust worthy garage can do this easy fit for your self if you have the time or know how you have the likes of MRC, AMD, MTM ect in that neck of the woods

AMD Technik
Unit D2, Telford Road
Bicester
Oxfordshire
OX26 4LD
01869 323205

QTS
4 Bridge Road,
Haywards Heath
W Sussex RH16 1UA
01444 451542

MRC
Unit 5,
Mead Park,
Thorpe Mead,
Thorpe Way Industrial Estate,
Banbury,
OX16 4RZ
01295 277308

[dace]

Any trust worthy garage can do this easy fit for your self if you have the time or know how you have the likes of MRC, AMD, MTM ect in that neck of the woods

AMD Technik
Unit D2, Telford Road
Bicester
Oxfordshire
OX26 4LD
01869 323205

QTS
4 Bridge Road,
Haywards Heath
W Sussex RH16 1UA
01444 451542

MRC
Unit 5,
Mead Park,
Thorpe Mead,
Thorpe Way Industrial Estate,
Banbury,
OX16 4RZ
01295 277308

There is APS at Brackley....Great outfit, with a wealth of knowledge

[Desmo]

.... for all the helpful advice. I'll let you know how it goes.

[Desmo]

Its taken me ages, but I finally took the plunge, took my RS4 to MRC for an RS6 8 pot calliper/disks brake upgrade, MRC Stage 1, H&R ARB's and new MAF. What a transformation !! Will post pics as soon as I can figure out how.

[Golich]

Glad to hear you are delighted with your transformed car.

Regarding the dealer who checked your brakes. To be fair to anyone checking the stock brakes, a visual and even detailed measurement of disk and pad thickness will result in all being well. The problem lies in exactly what you experienced some hard sustained braking will result in this rumbling or groaning and once or twice in my case an odd scaping noise. All of which had me convinced my brakes were shot. On inpsection by both the stealership and myself they were fine (On a few occasions). The scaping noise went away relatively quickly and for the most part I never heard any groaning or rumbling until you go for a spirited drive or apply the brakes for a sustained time say braking from approx 100mph.

So after 3.5years of this and one change of pads on what I'm sure are the orginal disks (67K miles I bought at 28K). I've come to the conclusion its simply the behaviour of the stock set up. So they were swapped out for the RS6 caliper B7 disk set-up and as you know the difference is amazing!

So on this occasion I'd give your stealer the benefit of the doubt on this issue. (This is an unusual statement from me with respect to my experience with stealers.)

[Desmo]

Golich, thanks for your feedback. I did find it concerning that the dealer was unable to see any issue with my stock brakes, particularly as brake-fade after just one hard stop on the road, was scarily obvious. As I am not a great fan of Audi approved main dealers, I had thought this amounted almost to negligence, but it seems reasonable to give the benefit of the doubt on this occasion. Regarding the whole issue of the 'approved stamp' I am still agonising over the decision to maintain a main dealer service history as the RS4 specialists seem to know so much more about these cars. However, unless every owner of a B5 RS4 makes a conscious decision to use specialists only, then I expect there is still much comfort and value to be derived from main dealer service history.