Another air matic problem S212

[Chestersmate]

Another dropping air suspension problem. It started very slowly a while ago, got more frequent and quicker so #I had to do something. Garage tried twice to find a leak, but couldn't, so the only option was to start replacing parts. I suspected air bags or pipework. Went for the pipework 1st (cheaper option). Now this is where I could do with some other opinions.
Since the pipework was replaced the drop is slower, back up to 12 hours from about 4 or 5, and about every 3rd or 4th day it stays up for a day or so. To me that suggests it won't be a whole in the air bags as the leak from that wouldn't improve. I'm thinking it could be either the seals in the valve block or the seals in the return valve in the compressor - both reasonibly cheaper fixes. What do you guys think?

 

[whitenemesis]

Have you run a diagnostic check using Xentry/STAR?

 

[Chestersmate]

Have you run a diagnostic check using Xentry/STAR?

Yes, I believe my garage has checked for faults. -they are an indy, not MB.

 

[AndrewOl]

Hi, the rear bags are a very common failure and the leak can be sporadic and hard to diagnose. How old is you E class? If you can get to the actual bladder it is possible to spray soapy water to look for fine bubbles. The material wears due to the action of road grime and go sort of porous rather that tear or hole you can see usually. When I changed mine I couldn’t see the leak until I had the old unit off.

 

[AndrewOl]

Meant to say that don’t be tempted to live with it as the compressor is working overtime and they are next to go. Ask me how I know!

 

[Chestersmate]

Have you run a diagnostic check using Xentry/STAR?

Yes, I believe my garage has checked for faults. -they are an indy, not MB.

Hi, the rear bags are a very common failure and the leak can be sporadic and hard to diagnose. How old is you E class? If you can get to the actual bladder it is possible to spray soapy water to look for fine bubbles. The material wears due to the action of road grime and go sort of porous rather that tear or hole you can see usually. When I changed mine I couldn’t see the leak until I had the old unit off.

Thanks for the response. It is a 2012 with 130,00 miles. My garage tried twice at different intervals with the soapy water, but no bubbles.
My query is that the leak has "improved" since the pipework and connectors were replaced, which made me think it wasn't the air bags, but maybe the fitting of the pipes to the valve block had messed about a bit with the valve seals reducing the leak. I just thought that at about £200 to replace the valve block might be worth a gamble before the expense of changing both airbags.

 

[AndrewOl]

I think the e class bags have a rubber boot over them which will make finding a leak tricky. It is a fairly simple system so you will get there in the end. For me I would start with the most active component but there is only one way to really find out if it is the block or the bags! Are both sides going down equally?

 

[Chestersmate]

I think the e class bags have a rubber boot over them which will make finding a leak tricky. It is a fairly simple system so you will get there in the end. For me I would start with the most active component but there is only one way to really find out if it is the block or the bags! Are both sides going down equally?

Yes, both sides are even. Took a long time (6/7 moths) to progress from occaisonaly going down to going down in about 4/5 hours. Now it takes about 10/12, and sometimes 2 days.

 

[AndrewOl]

Maybe it is the block then as it is unlikely each bag is leaking at the same rate. They are of an age though so will need changed out at some point. Not sure how yours is configured, I take it is air only on the back? If there is no receiver then there really is only the block and the compressor. When you start it raises to the correct level? If it is then it would seem the control side is good.

 

[Chestersmate]

Maybe it is the block then as it is unlikely each bag is leaking at the same rate. They are of an age though so will need changed out at some point. Not sure how yours is configured, I take it is air only on the back? If there is no receiver then there really is only the block and the compressor. When you start it raises to the correct level? If it is then it would seem the control side is good.

Yep, both sides equally down, and raise quickly up to normal height where it stays for about 10 to 12 hours after engine off. Only air at the back. Yes 4 components - air bags, pipework/joints, valve block and compressor.

 

[Chestersmate]

Maybe it is the block then as it is unlikely each bag is leaking at the same rate. They are of an age though so will need changed out at some point. Not sure how yours is configured, I take it is air only on the back? If there is no receiver then there really is only the block and the compressor. When you start it raises to the correct level? If it is then it would seem the control side is good.

I know the bags will need changing in the not too distant future, but trying to spread the cost.

 

[Chestersmate]

I've decided to bite the bullet and replace the air bags.
Got a pair of Aerosus ones, delivered to my house, £314 all in. I was quoted £400 plus VAT per Merc airbag.

 

[AntMB]

So glad I got rid of my air suspension, nothing but trouble.

 

[Chestersmate]

So glad I got rid of my air suspension, nothing but trouble.

What did it cost you you replace it?

 

[ChrisHGTV]

So glad I got rid of my air suspension, nothing but trouble.

I think it depends how you use the car to be honest. In my S212 it really comes into it's own on fully laden Euro trips. Doing the same kind of trip in my old Mondeo without self levelling you could really feel the handling dynamics of the car change (for the worse). But yes i guess if you're not doing that kind of trip it's of less value and adds complexity. Since i changed my airbags, compressor, valve and lines it's been good as gold. I think you basically have to treat the system as a consumable with a 10 year lifespan.

 

[AntMB]

I think it depends how you use the car to be honest. In my S212 it really comes into it's own on fully laden Euro trips. Doing the same kind of trip in my old Mondeo without self levelling you could really feel the handling dynamics of the car change (for the worse). But yes i guess if you're not doing that kind of trip it's of less value and adds complexity. Since i changed my airbags, compressor, valve and lines it's been good as gold. I think you basically have to treat the system as a consumable with a 10 year lifespan.

How you use the car makes no difference to the effects of the trouble it has.

When it was new and working properly, agreed, brilliant. When it gets to the triggers broom age, £££££££££££££££££££.

 

[AntMB]

What did it cost you you replace it?

Around £260 for the Arnott kit to get rid of it all.

 

[ChrisHGTV]

How you use the car makes no difference to the effects of the trouble it has.

When it was new and working properly, agreed, brilliant. When it gets to the triggers broom age, £££££££££££££££££££.

Sorry, should have been more clear. I meant the value of air/self levelling suspension depends how you use it. For me at least. If i didn't utilise it's ability to carry a full load while it preserved its driving dynamics i agree it wouldn't be worth the cost over coil springs and dampers.

My main frustration with it was just working out which part was leaking, rather than the cost. I think it went back to the garage 3 or 4 times in the end and i spent a good few hours underneath it myself!

 

[MrGreedy]

I seem to recall a lot of posts on the w212 bags having problems with the non-return valve at the bag in/out and the pipework fitting.
Obviously this would have been disturbed as part of new pipework fitted, and might have been improved but not fixed/fitted perfectly?

Might be worth having a look round threads for that?
Any advice on this area from forum helpers? (I have springs all round, so I have no personal experience I'm afraid).

 

[AndrewOl]

I've decided to bite the bullet and replace the air bags.
Got a pair of Aerosus ones, delivered to my house, £314 all in. I was quoted £400 plus VAT per Merc airbag.

I fitted a pair of Aerosus units to the back of the GL and they worked a treat.