I have a 2004 S500 and just hit 70k and last week I started noticing the front end down a bit low after sitting a day and this got progressivly worse.

Now the front end is extremely low and I get the airmatic too low to drive message. If I press the button to raise the car it fills up and raises. When I shut the car off it drops down again totally in about 15 minutes.

I heard a hissing sound inside the front right wheel well. I opened it up and sprayed some soapy water on the valve block and sure enough it bubbles up instantly. Is the valve block servicable? Does it have o-rings or do I have to replace the block? It seems to be leaking at the bottom of the block right above where one of the two studs that hold the valve block to the compressor.

Any help would be appreciated

Hi TSKW, I am having the same problem with my 2002 S500. Sprayed soapy water on valve block and am getting bubbles. On my car the front suspension sinks overnight, give warning messege in the morning and pumps up to normal in 20 seconds or so. Did you ever get an answer to your question about replacing o-rings or servicability of the valve? Thanks, Craig

I didn't get any responses and needed the car fixed so I brought it to the dealer and they replaced the entire valve block, about 1k to fix. If you don't do it you will burn out the pump too and then you will need to change that as well.