OMG! That's so logical!! Now this makes so much more sense to me, and I see just why you've indicated a malfunctioning level control valve best describes my 560SEL's present suspension issues. Thanks for the clear (and enlightening) explanation of the struts' and accumulators' isolated position as branches in the circuit.
Frank, in your earlier post, you indicated it's possible to rebuild the valve--though Max warned of difficulties he'd experienced in trying to do so with his. Is there a prepackaged kit available for accomplishing this? And is the rebuild procedure--diagrams, torque specs, etc.--documented either here, in the service guide, or elsewhere? (If feasible, I'd much prefer performing such a rebuild on my own, rather than shipping the valve somewhere and losing use of the car for too long.)
I see new level control valves selling online, and they're relatively expensive at around $400--though, I now understand how central they are to the functioning of the self-leveling suspension. If simply opening my malfunctioning valve up and replacing a few O-rings and gaskets is all it takes, that would obviously be a job well worth tackling...
Thank you for the education and direction!