SL55/63/65/R230 AMG: Which ABC Blocking Valve is leaking??
Thread Starter
Senior Member
Joined: Mar 2021
Posts: 272
Likes: 21
From: Rocky Mountains, Colorado
Just sold my '11 Porsche TurboS cab for an '03 SL55!
Which ABC Blocking Valve is leaking??
Frustrated and chasing my tail here trying to answer this question......any advice is appreciated.
- At first glance seeing the rear end well canted down to the passenger side with an inch or so difference from LR to RR, I thought it was the rear valve block seals. I resealed the valves it but found the seals and backup rings in nice shape. I stretched the springs too. No effect.
- I pulled the RR Blocking valve a 2nd time, seals all looked good, valve seat nice, worked the poppet into the valve seat in case there was a flaw I couldn't see and stretched the spring a bit more...…...no effect.
- That led me to start thinking that the RF was the corner that was sinking, and thus pulling the LR up, making the RR look high, and to some extent puling the RR down too.
- So I resealed the Front valve block, (seals and valve seats looked fine also) stretched the springs......…no effect.
- Engine on it sits level (about 27.5" up to each wheel arch) and the driving functions all work fine (it just bugs me to see it droop unevenly).
- Drooping can be seen within 10-15 minutes after shutoff.
- I have recently replaced the RF strut, all 4 accumulators, and both rear strut boots, but I can't link any of these repairs (carried out at separate times) to this fault (wasn't paying close enough attention).
- All of this started, or I noticed it, after recently acquiring the car having the red ABC warning flash over bumps prompting the accumulator replacements which occurred at separate intervals). At time of acquisition it had just had a new pump and reservoir and the fluid was in nice condition. It seemed that it was holding level (I didn't note the drooping in any case).
- It was suggested that I monitor the strut height values with STAR which look fine with the car running ( auto height calibration has been performed a couple of times + various actuation cycles which all look fine). Engine running these values look fine and immediately upon shutting the engine off, they move along the lines of the drooping/raising noted above......….no surprise here, but is there a way to use STAR to diagnose my issue??
Member
Joined: Aug 2015
Posts: 76
Likes: 18
From: Central Florida
06' SL65, 96' S500 & 09' S550
I assume you've read through this site;
https://mercedes-abc-drive-carefully.blogspot.com/
I haven't had to chase issues on mine before, the left front settles after a few weeks, but no big deal as soon as I turn the key. Based on your having serviced the valve blocks and accumulators, maybe replacing the RR strut is an option. Good luck, hopefully someone with more hands on knowledge will chime in.
https://mercedes-abc-drive-carefully.blogspot.com/
I haven't had to chase issues on mine before, the left front settles after a few weeks, but no big deal as soon as I turn the key. Based on your having serviced the valve blocks and accumulators, maybe replacing the RR strut is an option. Good luck, hopefully someone with more hands on knowledge will chime in.
Thread Starter
Senior Member
Joined: Mar 2021
Posts: 272
Likes: 21
From: Rocky Mountains, Colorado
Just sold my '11 Porsche TurboS cab for an '03 SL55!
Thanks Zoso7, much appreciated. I had reviewed something very much like the link you provided, but this is a much more thorough version.
It gave me a clue that I hadn't considered too; that being that my RR control valve is leaking allowing Accumulator pressure to bleed into the RR strut after the engine is turned off. If that's the case, it would (is) raising the RR, making the LR appear to be leaking down (drooping) when its not. And additionally making the RF dip a bit (also what I'm seeing). So I'll be taking a good look at that RR Control Valve next.
Also, for all of those interested, I put the same post on the SL (non AMG) forum and received some very interesting trouble shooting, valve problem isolation information there that you may find interesting.
It gave me a clue that I hadn't considered too; that being that my RR control valve is leaking allowing Accumulator pressure to bleed into the RR strut after the engine is turned off. If that's the case, it would (is) raising the RR, making the LR appear to be leaking down (drooping) when its not. And additionally making the RF dip a bit (also what I'm seeing). So I'll be taking a good look at that RR Control Valve next.
Also, for all of those interested, I put the same post on the SL (non AMG) forum and received some very interesting trouble shooting, valve problem isolation information there that you may find interesting.
