Vibration under braking

[KernowPete]

Hi guys
I bought my 07 RS4 three months ago under the used approved scheme. But over the last few weeks it's developed a vibration under braking that you can feel (and see) through the steering. It's usually at its worst when the car is warmed up and definitely worse when you're going downhill. Its gone in to my local Audi dealer today (which isn't where I bought it) to be looked at but the early diagnosis from them seems to be warped discs. If this proves to be true, does anybody have any thoughts/experience as to whether this would/should be fixed under the UA scheme?? In the three months I've had it, the car's covered less than 2000 miles and hasn't been driven at all hard. At the moment I'm waiting for both my local dealer and the supplying dealer to get back to me but I'd appreciate any info...
Cheers

[P_G]

You should get it under the RS approved charter but there is a big element of dealer goodwill on this as Audi UK only pay for a fraction of the parts and labour costs and will happen one time only. You may be as well getting the discs skimmed. Technically it is not warping per se; the cross drilled holes get clogged up with soft OEM pad material and this creates heat high spots which creates judder.

Skimming and changing to EBC yellowstuff or Ferrodo DS2500's works for most on here. There are plenty of threads about this on the forum, just do a search.

[KernowPete]

Just collected the car from the dealer (Truro Audi) and they're going to submit a warranty claim. Should hear in a couple of days whether or not its been successful. If it hasn't I'll be stright back on here for advice!
Out of interest, what do new discs cost??

[wrekka]

Audi dealers want a lot! Around 2 grand for front and rear discs and pads too.

You can get OE front discs outside of Audi for about £550

[StuBee]

Had the same problem with mine since i got it 8 months ago. Since then i've had 3 sets of front discs and pads on it all under warranty. Audi now have a cunning plan to fix it so its going back to them on the 14th for another fix.

[KernowPete]

Stu, is yours a used approved warranty?

[StuBee]

yeah still approved warranty, its an 06 plate so its not exactly a new one. Its Edinburgh Audi that have been doing the work. I'm not sure off the costs as they have been picking up the charge. When i test drove the car the salesman assured me it would be fixed.

tbh they have been quite helpful about it all. i think they can understand the fact i'm getting a bit peeved off about the whole thing! I wouldnt expect an "approved car" to constantly have to be going back to them. I'll let everyone know the current fix if it works when they put it on!

[KernowPete]

The problem with mine didn't show up in the test drive at Salisbury Audi. But it has appeared over my three months of ownership. It could well have been there on my test drive but the route they took me on was pretty slow with not much heavy braking so it may not have shown up. Whatever, it's in the hands of Truro Audi and the warranty people now, I'll let you know how it goes. Sounds like Edinburgh Audi are pretty good, but a bit too far from Cornwall....

[JohnnerLad]

Do they think this is normal or something has failed somewhere?

[KernowPete]

I don't know yet, but I certainly don't think it's normal. The very fact they're putting a claim in suggests to me they don't think it's normal either but we'll see what the warranty people think. I bought used approved because I thought it protected against this sort of thing, I'll be bloody p*ssed off if it turns out that it doesn't.

[adsgreen]

Just curious, but what kind of useage does your car get?

[KernowPete]

Just normal road driving. A roads, B roads and dual carriageways. I've had it just under 3 months and done just under 2000 miles in that time. It's probably used 3-4 times a week and I don't drive it any harder than I did with my ST220 which never put a foot wrong in the four years I had it.

[adsgreen]

Now not guaranteed, but that may be the problem - the brakes on the rs4 are larger than average and need to be used and used firmly bordering on hard.
No different to the fact that the engine needs an Italian tune up now and then so do the brakes. Going too easy on the brakes can cause the symptoms you have highlighted even within 2k miles. I had the same happen to my old VXR8 (which has even larger brakes) which was under 2k miles brand new and run in perfectly. It just seems that large performance discs/pads are very sensitive to being under used.
A guide that I use now is that if you are slowing down slower then what you get letting your foot off in 1st gear then too light. Also don't sit at the lights with the car resting on the foot brake.
As an aside, the new V8 M3 specifically states that the brakes are performance units and in order to maintain peak operating efficiency need to be driven in the manner to which the car was designed.

Don't take this as a criticism - it's not ment to be. I consider myself to be an accomplished driver both on the road and track (with qualifications and trophies too) but I didn't first fully accept this until I had the disc's looked at in a lab. I changed the way I drove slightly and never had the problem again in 10k's miles. It's just very easy to go from one type of car used to one type of driving to another that needs a tweak. With me I went from unservo'd discs to massive over assisted lumps.

[KernowPete]

Thanks mate, not taken as criticism at all. I'm still getting to grips with the leap up in performance from my ST220 (which I absolutely loved and I think is a criminally under-appreciated car) and any advice that can help me get the best out of the RS gratefullly received.
Anyone else got any thoughts on ads comments??

[Steve_C]

The more I read/understand about the RS4, the more I realise the car should be driven in the manner in which it was designed. So +1 for ads comments.