1997 SL600....Rear ADS won't lower
 

Ok...I'm new to MB and to forums. I have a 97 SL600 that I've had for 5 months. Out of the blue after driving for about 50 miles, I noticed when I parked that the rear end was high..looked like an old muscle car. The car sat for about 8 hours and was still the same, had to drive it home that way. It was low and level before I took off that morning. Any ideas to the issue? Never done it before. THANKS