DRC Goodwill no more

[HYFR]

you da man

[ArthurPE]

if I have my car when the DRC gives up the ghost and I can't get Audi to fix it
Bilstein struts/shocks
new front/rear strut/shock mounts
H&R springs
everything can be had for less than $900 delivered

simple, reliable and robust

Would you rip out all of the DRC junk completely? e.g central valves etc or just leave them in empty/dry.

I'd remove just the hoses and struts/shocks, I'd leave the lines and valves inplace

[grizz]

As you know we fix DRC in house , The system is much better than any coil over set .

If they " mist" they loose pressure and so don't work correctly. I've only had to replace 1 valve out of the 15 or so cars we've repaired .

[grizz]

As you know we fix DRC in house , The system is much better than any coil over set .

If they " mist" they loose pressure and so don't work correctly. I've only had to replace 1 valve out of the 15 or so cars we've repaired .

[ArthurPE]

As you know we fix DRC in house , The system is much better than any coil over set .

If they " mist" they loose pressure and so don't work correctly. I've only had to replace 1 valve out of the 15 or so cars we've repaired .

that would be my first option
if it lost pressure over time and no big blow-out
I'd get the system charged and see if it held pressure
if only 1 bad shock, replace it

problem is in my parts no indies, only dealers

honestly, even if not having noticable issues I'd have it pressure checked every couple of years, and if low, topped off

[adsgreen]

Agreed- the only one to watch out for is actual fluid leaking as then the shock to shot to hell.

Arthur - did you get all yours exchanged for updated Gen III units under the recall?

[ArthurPE]

my thoughts on DRC
great system
all shocks fail and need replaced
all hydraulic systems leak (look at a construction excavators cylinders/actuators, but they have a pump/resevoir to maintain pressure, ours is intitially charged and has a spring/diaphram, no mechanism to make up for leaks)
that is why Audi says sweating is normal, no such thing as a perfect seal (or anything)

if I had the tools I would do this
install a pressure gauge between the 2 circuits with petcocks, then you could open each valve to read the pressure
(or if pressures are slightly different, but the avg is within spec, open both and equalize the 2 circuits)
charge it to the hi end of spec, say 14 bar (iirc low is 12), then check it every 6 months, record it and the ambient temp
if it took 3 years to get 12, then just recharge it, imo normal, and no issue
it's probably not noticable until 10 bar or so, clunking, shudder, etc.

if it was leaking faster I might try a slightly thicker oil or some seal conditoner or leak stop (they make this stuff for hydraulic systems)
then charge to 14 and observe, if the charge bled off quickly, find the leak, probably only 1 shock

low pressure accelerates wear, since the system pressure is low, an impulse (bump in the road) faces less resistive force, so move faster (F = ma) if it moves faster it makes more force/shock to the system and wears and leaks at a higher rate, so keeping it in the spec range is important

DRC has an advantage, where as regular shocks need tossed, the DRC can be recharged when low (as long as only normal rate of leakage)
look at it as rountine maintenance
don't some coil overs need rebuilt every so often? removed, shipped off, and rebuilt
the DRC, just hook up the tool and do the procedure

edit: dear lord, the tool is $1800! http://audi.snapon.com/Search.aspx?sear ... rd=VAS6544

it's been done: found while googling for the tool http://forum.rs246.com/viewtopic.php?f=2&t=95630

[neckarsulm]

I didn't know Unit 20 could work on DRC, great news

[adsgreen]

Yes top shocks such as ohlins are rebuilt but that's to keep them in spec. They are machined to incredible accuracy and control but it's the adjustability that adds the problem. I've always thought that it's similar to a torque wrench losing its calibration
But it's the valves that are rebuilt - recharging drc will only go so far before something similar would need to be done.

That being said I am a drc evangelist and I've tried many shocks. By far the best 'normal' road car shock that can take a wide variety of conditions. And the fact it's pure mechanical engineering with no electric anything is a real triumph.

[Brooner]

After talking with my dealer they have agreed to go halfs on the misting shock as the goodwill agreement is no in the hands of the dealers and is based on service history and loalty to the dealer so happyer but i would have been nice for Audi UK to announce this to all the RS4 owners rather than having to phone them to get the information so car booked in for shock replacement and also the undertray and hydralic engine mount an expensive month
MOT 40k service and road tax and these extras but hey no pockets in a shroud

[robcarp1967]

Hi All
not to sure how the drc works ,but had the nsf replaced last year by audi doncaster,under the goodwill agreement ,front shock and valve were replaced,, i have now found out that the osf has leaked,,is the shock and valve one complete unit,, or can just the shock be replaced,spoke to audi doncaster a couple of days ago,,they said i would need to take it in for there techs to have a look at the leak,,because they can't take the word of an independant garage,,and the fact that i was stood there when he found the leak.

[PetrolDave]

The valve block is a separate unit from the shocks, it controls the diagonal linking.

If a shock leaks badly it normally leads to valve damage requiring the valve block to be replaced - which is what happened to me recently - and the valve block is the expensive part

[stu]

[...]low pressure accelerates wear, since the system pressure is low, an impulse (bump in the road) faces less resistive force, so move faster (F = ma) if it moves faster it makes more force/shock to the system and wears and leaks at a higher rate, so keeping it in the spec range is important[...]

I hadn't thought of that. My DRC has never been touched as it hasn't had any problems. Maybe I should have done it before now but I was of the 'if it ain't broke' school of thought. Combine that with a mild fear of Audi techs and you can see why I left it alone. It'll be interesting to see what effect five years have done on the pressure.

I find my car's handling is influenced a surprising amount by changes in tyre pressure brought on my our weird summer and/or sportier driving. I'm checking and adjusting them loads. When the tyre pressures are spot on the car drives great. Could my car's apparent intolerance of varying tyre pressures (springier tyres) be a symptom of under performing shocks? I'll have the DRC answer in a few weeks but I just thought I'd throw the question out to you guys in the mean time.

[robcarp1967]

yeh i know £734 +vat,,wonder if ebay have them,,i'd doubt it

[PetrolDave]

Could my car's apparent intolerance of varying tyre pressures (springier tyres) be a symptom of under performing shocks?

It could be an indicator that the damping isn't correct, and you're in some way compensating for that by changing the softness/hardness of the tyre sidewall by changing the pressures?