Think my DRC has failed

[Pistolpete2543]

For a while now I've had a slight knocking from front drivers side. I have checked the shocks many times since owning the car but all 4 have always been bone dry. I was therefore looking to replace the front control arms as this was more likely to be the cause. Anyway, left the car for 2.5 weeks while on holiday, and when I first drove car again I immediately noticed the front drivers side rattling & knocking much worse than before, and also a rattling from passenger rear (which would clearly imply DRC failure).

1. Is it possible to have a failed shock with no sign of any leakage? I haven't had a proper look yet, but if all still dry, is the only way to be definitive on failure to pressure test system?
2. Why would DRC completely fail whilst car sat idle for over 2 weeks?
3. I prefer to keep DRC, but on an 11 year old car it doesn't seem right to replace a single damper or just a pair of diagonally opposite dampers. Is it ok to do this, or should I really replace all 4 to make it right?
4. Anything else to replace while I'm at it? (e.g. Front top mounts?). I'm assuming the central valves will be ok.

If I do all 4 dampers + flexi hoses I'm looking at £1600 in parts, so about same price as KW V3 coilovers. Would appreciate advice.

[MikeFish]

It might not be just the dampers themselves that leak. The metal lines that supply the fluid corrode and could possibly be leaking too. Have you checked these?

[Pistolpete2543]

I have checked the lines in the past. I cleaned them up and applied Bilt Hamber protective coating on them to prevent further corrosion. However, could not access the full line lengths due to the way they run. But yes, I still need to check and see if a line is causing the leak.

[MIDZ]

Jack it up and have a look at your springs, I had a broken rear left spring where a small bottom section had snapped off and was lying in the wishbone/link...I never heard any rattle but it might be something to check before all out big bucks...

[eliano]

Someome is selling nearly new set off kw v3 on fb group for £800

[Pistolpete2543]

Someome is selling nearly new set off kw v3 on fb group for £800

Would you have a link? I can't find them.

[marc1]

I've got a full working set of V3 DRC if you wanted to still with OEM.

[eliano]

Cant link as its a closed group, send a request to rs4oc(uk), theres a separate selling page to which is rs4oc buying/selling , be quick as theres some interest but still look unsold

Someome is selling nearly new set off kw v3 on fb group for £800

Would you have a link? I can't find them.

[Pistolpete2543]

Mike, you were spot on. Just had a proper look there and it is indeed the hard line up beside fuel tank. Think I'll bite the bullet & replace them all at the same time.

[Pistolpete2543]

Thought I'd update this thread, I've been toiling over what to do, trawling the forum for opinions and advice on DRC vs coilovers. Call me a purist, but I love the RS4 in its original form, and really love the DRC system (if only it were less troublesome). So I've decided to stick with it and just bought the 4 hard pipes for the DRC. Audi really have a monopoly on these systems, as there are no afternamrket options for pipe work, flexis or dampers. The 4 pipes alone cost £870 which is extortionate. I bought a good used set of v3 dampers from a forum member, even though my current dampers are fine I thought this would be the time to change them all for newer items. All in, I'm spending close to the same as KW V3's or Bilstein B16's (not inc fitting). I hope I've made the right decision.

[BillTheButcher]

Thought I'd update this thread, I've been toiling over what to do, trawling the forum for opinions and advice on DRC vs coilovers. Call me a purist, but I love the RS4 in its original form, and really love the DRC system (if only it were less troublesome). So I've decided to stick with it and just bought the 4 hard pipes for the DRC. Audi really have a monopoly on these systems, as there are no afternamrket options for pipe work, flexis or dampers. The 4 pipes alone cost £870 which is extortionate. I bought a good used set of v3 dampers from a forum member, even though my current dampers are fine I thought this would be the time to change them all for newer items. All in, I'm spending close to the same as KW V3's or Bilstein B16's (not inc fitting). I hope I've made the right decision.

The more miles I put on my RS4 the more I realise how good the DRC is. As you say, it's such a shame it's so problematic. I hope you have many trouble-free years and miles ahead.

[hector8]

Keep us posted on how you get on. What it feels like etc.....
I am on 59k miles and probably nearing a few big costs soon.

[SimonS4MTM]

I would say I love the DRC also. Hoping mine keeps going for a long time to come. I am on 97k. The previous owner changed a front right shock around 85k.


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[maars]

DRC dampers and adjustable KW springs is a great setup. Perfect stance, awesome handling, and more comfortable than standard.

[Pistolpete2543]

So I'm back in business, picked car up this morning from Audi after having the DRC system recharged. All the replacement parts (DRC pipes, v3 dampers and I also changed both engine mounts for 034 Motorsport items & a new genuine tie rod end) were fitted by local Indy McEvoy Motors who really know their way around the RS4. I would highly recommend them for anyone in Northern Ireland. To be fair, Belfast Audi were also spot on for the system recharging which cost £220 inc the hydraulic oil.

The difference in how the car feels really is night and day. Although I previously haven't had any leaks on the system, I'm certain the system must have lost some pressure over the years. The suspension now feels much firmer than before, the whole thing just feels tight compared to before. Obviously only time will tell if this proves to have been the right decision depending on future reliability, but a perfectly functioning DRC system really is a joy to drive. It's cost me about the same as a new set of B16's or KW V3's fitted.