Calling all ADS and hydraulic suspension gurus

[PHAB]

Hi all,

One for the technically minded out there. Issue driving me slightly nuts on my 1998 SL600. Im slowly rebuilding what I can on the car (documented on another thread) and have recently had the rear lower arms off for new outer ball joints and to check ADS2 struts, rear ARB, ARB mountings, ARB rods, bearings, spring cups, links etc etc etc - the lot.

It all went as smoothly as can be expected, everything is now immaculate but I am sure there is an issue with the ADS system on the rear right wheel. Its sitting about 1-1.5cm lower than the rear left which in turn is bringing up the front left. There are no warning lights, the car drives like silk in a straight line but Im thinking there is extra roll onto the rear right in left hand cornering, that is not present when turning right. It may be placebo but sometimes it also feels like the car is losing height on the rear right when in motion, which obviously plays havoc with the suspension geometry and tracking. In addition, the rear right has a clicking/knocking when one -bounces- the rear right suspension. The suspension travel is very supple so the globes are fine...but something is up! My question is....can an ADS strut go bad with no visible signs of leakage or anything else untoward? Do they have limited lives like a conventional shock?

Everything else on that corner is new...every bush and ball joint is new etc etc The car ride height control raises and falls on the button correctly, albeit slowly etc.

Over to the experts....

 

[BTB 500]

Sounds like a broken spring?

 

[PHAB]

Have had both rear springs out during the rebuild and both are OK....unlike conventional setups the shocks in ADS set the ride height of the car....still head scratching. Thinking the valve for the rear shocks might not be fully closing allowing fluid to travel back to the front valve block when the shock is depressed, rather than only to the sphere for each side. Would expect it to throw a code for this though?!

 

[BTB 500]

Have had both rear springs out during the rebuild and both are OK....unlike conventional setups the shocks in ADS set the ride height of the car

AFAIK the ride height is only set front/rear ... there aren't separate sensors for each corner. So you can get a variation between n/s and o/s depending on the state of the springs (e.g. I was told it's quite normal for the driver's side to sit slightly lower). I did assume you'd had the springs out so it was unlikely to be the cause, but thought it was worth mentioning!

As an aside, have you got the ADS II manual? If not a scan of it is available on various websites, found this one via a quick Google:

http://bayhas.com/r129manu/r129-ads-ii.pdf

Worth downloading and keeping somewhere safe!

I see you are in Surrey - if you get stuck you know there's an M-B ADS specialist near Weybridge called SS Motors? They replaced the accumulators on mine a few years ago (a routine job, but they are very knowledgeable).