could be a sketchy control valve, then? I dunno.

 

Sorry for the very late response.

I see from posts that your car is a wagon and does not change level between Sport and Comfort modes so my theory does not apply.

I have car with full AirMatic and it changes level about an inch between the modes. When i had a leak in the left rear spring the car went all the way down if I left it n Sports but it did not go all the way with Comfort. You could see the left side lower but it was not all the way down.

This bothered me a lot and made me do lots of work on the system and I replaced the valve block as it seemed there had to be an intermittent leak problem with a valve since a leak in the spring would always make car go all the way down, right?

Not so , and my theory is that when left in the higher level Comfort mode the good spring has enough stroke to develop pressure to hold the car up while in Sport mode the springs bottom out before enough pressure is generated.

With wagon this does not apply if the level is the same between modes.

I replaced both rear springs with Arnott and problem solved.

 

I had a similar problem with my 2011 S212. When I first started having the issue, the left rear on the vehicle would drop overnight randomly while vehicle was parked. I would hear the compressor kick on during start up to level the system and occasionally when I was stopped at a red light or stopped momentarily say at a drive thru and could hear ambient sounds. This started occurring around the 75k to 80k odometer mark on my vehicle. I did my research and came to the conclusion that my left side air bag was leaking slowly and inconsistently at first and it began to progress to slowly and consistently as time and mileage accrued. I basically took a wait and see approach to this problem because I didn't get the dreaded rear height malfunction with the associated picture graphic on my dashboard display...that is until one day last summer while driving on a parkway near my home and the malfunction light came on while driving 65 mph and the rear of the vehicle bottomed out. I was able to limp the car home safely and ordered the Arnott replacement airbags.

The diy is simple if you are mechanically inclined and have the appropriate tools...there are plenty on tutorials on here and YouTube that will walk you through the repair procedures. I replaced both rear air bags ...I figured it was just a matter of time and inevitable that right rear will start to degrade as well and solved my problem. Inspection of the removed airbags showed general degradation of the rubber bellows but no visible punctures or holes on the left side air bag as compared to the new Arnotts. The air bags degrade over time and don't necessarily have obvious signs of tears or such. The vehicle now holds the air in rear for weeks at a time and at the appropriate height.


Hopefully my experience helps in your understanding your vehicle's problem. Good luck with the repair.

 

Are these documents valid for VIN WDDHH8JB5DA728493

 

See attachments.

 

Howdy Konigstiger ... Is my chassis code 488 (steel/air suspension) ?

 

No, ‘function’ sheet covers for the most part operation of standard front shock / rear air ride combination.

 

Copy thanks. The Parts_Information.pdf file listed my chassis as 488.

 

-488 not +488

 

I've seen many airbags like these always fail on MBs and BMWs at around 80k. Would be great if you can pinpoint the leak source first but I would also change the bags if the have over 80k as well.