E Class 350 Sport, rear air suspension.

[Beardz]

I’m not sure Xentry always picks up leaks, two indys looked at mine when it was leaking and nothing was showing.

from what I’ve seen on here at about 10 years old the system on the S212 starts having issues.

Having finally sorted mine after 5 visits to two indys and basically replacing the whole system for £2k I would suggest the following. First replace all the air lines as this is relatively cheap. I would consider the air lines almost a service item. At 10 years they go a bit brittle and there are various places they can rub on the car to cause leaks which can be almost undetectable. If it’s still dropping evenly on both sides you could then swap out the valve block as thats quite cheap and also check the compressor for leaks. If still dropping I would then look at replacing the air bags.
My issue was a combination of leaking air lines and a compressor. But i had one air bag replaced first then thought I may as well replace the other. So on mine I’ve replaced everything and it doesn’t drop at all even over two weeks.

I have to say although it was quite costly to do it’s nice knowing it should be fine now for a good few years.

This is the method I applied to mine. Lines changed first (approx £300 with an indie), no joy, went to do the valve block next but discovered both airbags had tiny leaks so replaced the pair (bought via online app called Autodoc, bought Arnotts for under £500 and had local mech fit for £150).

 

[Londonscottish]

This is the method I applied to mine. Lines changed first (approx £300 with an indie), no joy, went to do the valve block next but discovered both airbags had tiny leaks so replaced the pair (bought via online app called Autodoc, bought Arnotts for under £500 and had local mech fit for £150).

I took a similar approach although I skipped the 1st two steps. My local garage said "it'll be the bags". I said "can you check the airlines first?" so they did a soap test on the parts they could access and then said "Honestly, it will be the bags. They fail on these".

So took the gamble and, in my case anyway, it was the right thing to do; it was indeed one or both bags. Even if it was just the one (OSR) the other one would probably have failed soon.