IanF11 Posted May 7 Share Posted May 7 Hi All, Appreciate this has been done to death, but can I just check my understanding on the system. The car went down on both sides, the compressor runs and the suspension does not rise at all. If a bag had split I thought at least one side would inflate or does the failure of one bag cause these symptoms. Absolutley no warnings of faults on the Vehicle Info screen. Car is a 2011 520D. Thanks. Quote Link to comment Share on other sites More sharing options...
HandyAndy Posted May 7 Share Posted May 7 With both sides equally down and the running compressor having no effect, I'd be looking either at failure of the compressor (running, but not actually pumping) which has several fail points possible, or less likely, failure of both output airlines. Leaning towards the compressor if it suddenly failed to pump, I'd not expect loss of existing pressure. Failure of the control valve sounds more likely. I believe it has been repaired by some, but unless you can narrow it down to that specifically and fancy a repair attempt, you might be better off swapping out the whole compressor assembly... unless you can get a separate replacement valve. I'm sure one of the guys will be along shortly with better directed advice..... Quote Link to comment Share on other sites More sharing options...
duncan-uk Posted May 7 Share Posted May 7 When mine sank both sides it was the relay (compressor wouldn't pump) so as Andy says suspect compressor isn't compressing! There seems to be an issue with the dessicant getting wet or valve sticking (i think) all quite repairable and easy enoigh to strip down if so inclinded. Quote Link to comment Share on other sites More sharing options...
IanF11 Posted May 7 Author Share Posted May 7 Thanks all. It failed when I loaded up the car with 4 passengers and a bootfull of drink/bags on our way to a weekend party! I'm guessing the valving must have given up for it to drop immediately. I will take the compressor out and have a poke around. Quote Link to comment Share on other sites More sharing options...
IanF11 Posted May 9 Author Share Posted May 9 Quick update: There were soft black filings everywhere in the cylinder and I'm guessing they are the piston ring so new one ordered from 4x4 Air. The decompression solenoid worked fine but I did discover that the replacement that comes up on a Google or ebay F11 search is different to the one on my car. I did some digging and it's the same as the one fitted Mercedes 220 estate . Fingers crossed. 2 2 Quote Link to comment Share on other sites More sharing options...
IanF11 Posted May 15 Author Share Posted May 15 The outcome: I changed the piston ring which didnt fix the issue, however, the old ring was shredded so it had to be done, but I did notice there was some air released when I undid the air lines to the aire bags. I had another look at the compressor on the bench and noticed a piece of metal lurking in the the non-return valve. Took the screws out, removed the offending item, cleaned the valve, reassembled the compressor and voila, all is good. It's still working after a road test and 24hrs later. The only issue is where did the small piece of metal come from?! That will have to stay a mystery for the time being, too many other jobs to do. Thanks to all for the help. 2 Quote Link to comment Share on other sites More sharing options...
Percha Posted May 15 Share Posted May 15 Well done, I have only every changed air bags so far and I assume if I keep mine compressor/valve block etc will come at some point Quote Link to comment Share on other sites More sharing options...
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