S600 Suspension Light

[Pavel]

Hey everyone

Our '94 s600 has an annoying problem. When the car is driven for a while, (warms up), then parked somewhere, switched off... come back, start the car, and the Suspension Light comes on the dash (2-3 seconds after car started). This seems to be accelerated when parking on a curb (so the car isn't level).

Once that happens, the rear suspension becomes rock-hard, and very annoying... The problem goes away after a while (usually drive a bit after, then switch off ignition at traffic lights, restart and sometimes it disappears).

Never appears when starting for the first time of the day (engine cold).

Led to believe that it's the hydraulic fluid since upon checking the reservoir in the engine bay, the dipstick said it was over the max line (just about covering the M)... Thinking this could be it (expanding when hot would make it even more than max), syphoned a bit out of there until it was JUST below the max line (.5mm perhaps). The problem seems a lot reduced now but still appears every so often.

Anybody have any ideas? Should I just syphon a bit more out of the reservoir till its a good few mm below the max line? It does make sense since as it heats up the fluid would expand triggering the sensor?

Thanks a lot