I am was having an issue of the rear sitting very low when parked, when I started to drive it, it was bouncy and would then raise up and I took it in to the Mercedes Dealership/Servie, they first replaced my valve block, said it was bad, did same thing, took back again and then they said it was the compressor so replacing that, another $ 1500 and now they just called and told me that both air bags have a leak and they need replaced. I was like WHAT?? So my question... is it possible the valve block and compressor is both bad along with both air bags leaking?? I feel they are doing a bit of trial and error to see what is exactly wrong and charging me a killing. Please let me know your thoughts if all 3 could actually be bad. Thanks

 

Normally you would start with replacing air bags, don't you? Cause they cheap and any mechanic can change it on the budget. Anyway it is "too late to apologize"

 

that’s is what they should have done from the very beginning. Replace the whole system. I had a bunch of problems and I at first replaced the rear bars front bags and then valve body and compressor as well as the in line filter. No problems since. Having Mercedes do that would have been like six grand.

 

I am going through the same right now. Had a random sagging in the rear. The compressor did overheat so I replaced that. 30 days later i got the sag again, i am going to try the valve block.
Honestly, the parts are cheap ~$200 each at Arnott or FCP. It litterally takes less than an hour, the only think that needs to be removed is the wheel well liner, not even the tire. I am sure you could do it yourself. Kills me waste $1000 on labor, plus the time to drive back and forth when you really could do it your self in an hour.

I sprayed down my bags, no leaks. Plus I find it unlikely that both rear bags would like at exactly the same time.

 

So, I replaced the valve block and I had a slight leak in one line that caused the compressor to overheat. The message was compessor cooling. Now I have the malfunction warning on the dash. The front two shocks are fine, the rear is sagging again, it worked until the compressor over heated, ran too long.
It seems that the compressor is no longer going to run, that it has some sort of safety mode that prevents it from running, I have unplugged it, no luck.

Any ideas on where to start next? The compressor is about 45 days old, barely driven, the valve block is new. I dont believe I have a leak anywhere, I have sprayed soapy water everywhere, I dont believe the compressor is running at all. It does not make any noise.

I could put in the old compressor again, but I would be surprised if my new compressor failed. it ran for maybe 15 seconds before it shut off.

Any thoughts are appreciated.

Thanks,

 

I replaced one bag so far, the 40amp fuse is good. I still get the Suspension Malfunction warning, it does not appear that it is trying to run the compressor or do anything for that matter. The front end is fine. I have been reading about a reset procedure, but I cannot seem to find it. Any way to get the compressor to fire so I can check for leaks again? I will do the 2nd air bag tonight, but wanted to check my work thus far.
As a reminder, there was no error message until I replaced the valve block, and I believe there was a leak from one of the hoses whcih I fiexed shortly. The error message came after the valve block replacement and now I cannot remove it.

It looks like I may need a computer? any way around that?

Thanks

 

I should have listened to arsupisemnet from the get go. He identified the issue as air bags. Apparently the drivers side was leaking. About every 30-45 days the rear would sag, both sides. Seemed unlikely that both sides would sag if one bag was bad. I repalced the compressor and the valve block. No luck.

Ocrams razor for sure, enough people have been through this that I should not of tried to out think the community.

The first bag took an hour, the second one 15 minutes. It is best to remove the wheel well liner to allow room to remove the bag. The ride height sensor did not provide enough room in my case. I probably could have forced it, but the liner was a better path.
Started it up and all is well, knock on wood.

 

silvergl - thanks for the info on indy mechanic. QUick question on your airbag change. Did you raise the entire rear and swapped the bags or did you raise one side, swap, bring it down and then do it on the other side? Thanks.

 

I did one side at a time, just how I had it jacked up. I see no reason not to do both at once. Probably jack itup in the middle somewhere. I did put it down between bags.

 

@silvergl Thank you, sir!

Am going to do mine this weekend.