On purchase of my 04 E320 wagon the air pump was bad, blown fuse and no air. Somehow it was pumped up and took months to bleed down and now has a great Arnott pump, good fuses and now four years later at 180K miles it has bleed down, only on the right rear. The shock that gets all the potholes. But sometimes the bleed down is rapid and other times, (so I know its not the air bag) it will hold beautifully. I just went for coffee and it bled down strongly pumping every 20 seconds and then stopped leaking and now its sitting just fine for over an hour.
So in my analytical thinking this MUST be a bad check valve that is failing to work and hold pressure, then it grabs and does the job. A bad bag would always leak, and electrical issues (are the check valves electrically actuated?) And there is a check valve in the shock and also on the air bag?
Anyway I have the foxwell scanner that will actuate the air system and supposedly operates left and right sides. Releases pressure and lowers and raises the car...Anyway I almost sent for air bags but I see its not that now after it 'fixing' itself. And Its gotta be check valves Im sure, just the right rear...Help diagnosing and repairing the bugger? I know the experts out there are on top of this symptom and thanks so much for your wisdom and experience..