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Thread: DRC Issue (Still) - Any Thoughts?

  1. #1
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    DRC Issue (Still) - Any Thoughts?

    All,

    I've had the DRC replaced with the upgraded version now for many years, and I always felt it wasn't working properly. The ride is particularly harsh (although, I am on Sportec 20" rims), the rear feels like it's bouncing around - especially when cornering or going over uneven surfaces (and, when I press on the rear bumper, it bounces several times before settling), and the rear rides high (I've posted photos of that, previously, which several have confirmed my comment). Yet, when I have taken it into the dealer, they have declared the DRC is working fine every time (and it's not riding high in the rear). And, importantly, no leaks (or at least, no tell-tale seepage where you would expect it to be). However, they've never tested it to verify that it's still pressurized. FYI, car has 71K on it.

    I had my car in an Indy shop yesterday for an oil change and asked them to do a once-over. The tech noted that the suspension rides "like a truck" during the test drive. He again inspected the DRC for leaks, but dry as a bone. The Indy cannot do the pressure test, as they don't have the tool. His comment to me was that "something's wrong", but he can't find the problem. He said it felt to him like the rear shocks weren't pressurized, but that would be impossible, as they are cross-linked with the fronts. So, if the rears are empty, the fronts would be, too. And, of course, if the system de-pressurizes, the shocks are then trash given the damage to the internals. So, it may be that it's time to bite the bullet and go coilover (KW or Bilstein, I suppose).

    Anyway, if anyone has any thoughts on what the problem might be, I'd be interested in hearing them.

    Thanks,

    CW

  2. #2
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    Quote Originally Posted by CornersWell View Post
    if anyone has any thoughts on what the problem might be
    This:

    Quote Originally Posted by CornersWell View Post
    I have taken it into the dealer

    You can always go with Koni sports & stock springs, I actually like them very much.

  3. #3
    Registered User mrdave's Avatar
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    My $0.02, the DRC dampers are very nice when working properly but I wouldn't waste any time or money trying to repair them once broken. As nubcake mentioned, Koni Sport shocks are a good and inexpensive option. And there are several decent sets of coilovers. I'm probably going to go with H&R coilovers (part# 29482-2) once my DRC gives up the ghost.

  4. #4
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    Yes, I agree that if the DRC isn't working properly, it's time to go to the coilovers. What's weird to me is that there's no apparent leakage, which you would expect if the DRC system has emptied itself. And, the car has, to the best of my knowledge, always been this way. Even when the DRC replacement was newly installed.

    The only thing left to do is to have the DRC pressure checked by a dealer and go from there.

    Thanks,

    CW

  5. #5
    Registered User Aronis's Avatar
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    And to think the New RS7 comes with that poorly implemented DRC. It's shameful. I passed on one for that very reason.

    Mike
    '18 BMW M5, '19 Porsche Boxster GTS
    (prior '94 325is, '97 M3, '00 A6 4.2,'03 RS6,'08 A4 Cab,'13 A8L,'15 Q7,'16 BMW M2,

  6. #6
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    Quote Originally Posted by Aronis View Post
    And to think the New RS7 comes with that poorly implemented DRC. It's shameful. I passed on one for that very reason.

    Mike
    Offtopic, but from what I know, the new 4.0 engine is also not nearly robust as the old 4.2. Although it's being pushed quite harder even in its stock form...

  7. #7
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    There is air in the system. Dealer failed to use the special tool the first time. What are the chances 5yrs later they learned?

    do they even have the special tool?

    Also the ride height was screwed up the first time. Do I need hit repeat?

    Koni or KWV3 and be done

  8. #8
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    Another view, the DRC system is easier to work on than brakes. An evacuation and recharge system can be cobbed together for not much money using (mostly) off-the-shelf items and NOS dampers are available and not that expensive (if needed). I did mine a year ago or so, and no issues since.
    RS6 - Mugello Blue/Silver, still on DRC and hope to keep it that way... Added RNS-E
    '73 Jensen Healey, Lotus 907-Powered

  9. #9
    Registered User Aronis's Avatar
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    Yes if done correctly it can be redone. You have to be very precise. The starting point is new factory charged Accumulators. You cannot recharge those in the shop since the pressure is 20 bar, i.e. 290 PSI. Perhaps a mechanical piston and screw setup could safely apply that much pressure to the mineral oil (that is what I have been told is the fluid in the system) but using a compressor and a hose would be dangerous.

    The guys who worked on mine back in 2006 (mine was the first reported failure on the east coast) had NO CLUE. They would not even consider listening to me. They replaced only the rear shocks and did not listen when I said that the seals on the fronts would be leaking as well. They used a new set of accumulators and failed to evacuate the system properly, resulting in the front of the car bouncing just like the rear had been. Thus they killed the front two shocks too. Then they tried just replacing the front shocks and using what ever remaining pressure was in the system, not much. I had them finally get 4 new shocks and 2 new accumulators and still they did not get it right.

    After the recall, the Marc 2 part of it (I really don't think they changed any part) was Marc 2 at TRAINING the mechanics on the system.

    The running joke was that the US techs had missed the first day of the RS6 training camp in Germany and that was DRC day!

    So after the recall the cars were CLOSE to factory but not quite. And that Marc 2 system failed in my car at 13 months. Just outside the warrantee.

    I have had KWV3 in since 109,000 miles so I have put 35,000 miles on them and they have been solid!

    My original DRC crapped out at 30k miles and the Marc 2 lasted about 20k miles.

    Mike
    '18 BMW M5, '19 Porsche Boxster GTS
    (prior '94 325is, '97 M3, '00 A6 4.2,'03 RS6,'08 A4 Cab,'13 A8L,'15 Q7,'16 BMW M2,

  10. #10
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    Accumulator can be repressurized with a cheap-o porta-power hydraulic pump. They're used in maintenance activities all the time, available on Amazon for ~$80 or so. 290 psig is much less than what is developed in a braking system.

    Not intending to be in your face, Aronis. Audi and a few indys have made the DRC put to be much more complex than it really is.
    RS6 - Mugello Blue/Silver, still on DRC and hope to keep it that way... Added RNS-E
    '73 Jensen Healey, Lotus 907-Powered

  11. #11
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    FYI if you do H&R springs along with Konis, the ride height will gradually become lower and lower as the springs start sagging. On my to-do list is to swap my stock springs back in because the way my car sits now is only good for being displayed at the SEMA show, or if I were 25. Being 45, I ain't got time for stupid low cars anymore.
    Das Silberkugel - Eurocharged Stage 2/MTM/Level 10/Hotchkis/Koni/H&R
    2015 Ducati 1299S Panigale
    2014 Ducati Multistrada Granturismo

  12. #12
    Registered User Aronis's Avatar
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    Quote Originally Posted by B727 View Post
    Accumulator can be repressurized with a cheap-o porta-power hydraulic pump. They're used in maintenance activities all the time, available on Amazon for ~$80 or so. 290 psig is much less than what is developed in a braking system.

    Not intending to be in your face, Aronis. Audi and a few indys have made the DRC put to be much more complex than it really is.
    No problem, its not that it is very complex, it is you have to follow the refill procedure to the letter! It's pretty well outlined. Replace the bad parts, start from recharged accumulators but first pre charge the struts to 5 bars. etc etc. When there were working on the system they just kept screwing up. It's not rocket science but it is a particular procedure.

    Mike
    '18 BMW M5, '19 Porsche Boxster GTS
    (prior '94 325is, '97 M3, '00 A6 4.2,'03 RS6,'08 A4 Cab,'13 A8L,'15 Q7,'16 BMW M2,

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