Hello, new member and first post, longtime lurker. I drive a 2012 CLS550. For about 2 years, the right rear end would lower over night, and when I started the vehicle, it would just correct itself. I knew there was obviously a leak somewhere, but I figured I’d go as long as possible before needing to dig into this crap. First off, about 3 months ago, I replaced the compressor and both relays in the engine and trunk, which worked fine. Now Last week I started my vehicle, and the rear end was slammed on both sides. The vehicle stated, “Rising, please wait." The compressor would cycle on and off with the Rising message displayed but no rise. I went ahead and replaced the driver rear air spring (which was absolutely crazy and was stuck beyond being stuck; I ended up taking the control arm off and using a blow torch and pry bar to get it out), which did not help. I replaced the air valve block today, and that also did not help. Now, after replacing the block when starting the vehicle, the compressor only stays on for 30 seconds, shuts off, and won't turn back on. The display states, “Car too low pull over,” and all four sides are slammed due to changing the valve block, which lets all air out of the system. I also noticed the rise button on the center console will not engage or light up red when pressed. My only thoughts would be that maybe the relays have gone bad, and that's why the compressor won't stay on and fill the system. If anyone with some knowledge on this could chime in, I would be so grateful.

I recently bought a 450 GLS
on second day I noticed the rear end lowered all the way, covering the top of the tires.
the next day, it didn’t happened.
i read the different threads, and every one talks about a leak on the air bags.
i have a Range Rover sport with same system, which I ended changing the suspension bags. In this case, the vehicle was lowered every single day.

i went out of town for 12 days. When I got back, the mercedes was at the driving high, exactly as I left it.
couple of dats later after driving it, it lowered again.
This week has been up and down. So at this point, I don’t think is a leak problem, because a leak, stays leaking. Wouldn’t hold 12 days.
also id i use the lift button, the car raises and stays there when I turn the engine off for days without dropping.
so I am sure they are not leaking. It might be something to do with the level sensor.

have anyone done something different than changing the bags. Has anyone tested this other theory?