E350 W212 Estate rear air bellows

[Candellara]

Our car is sitting quite low at the back every morning now. It raises fines and stays ok during the day.

Anyone changed the rear air bellows? What the cost from dealer or is it DIY?

Thanks

[Stegel]

Not a 212 but I’ve changed them on a S211 and believe they’re pretty similar. I used Arnott units and it’s pretty straightforward if you can get the car in the air. Large bolt through the bottom arm and they just pull off a plastic clip that grips a hole in the underside of the load area; a new clip came with the Arnott units. Electrical connection and air line just push into new unit, although the airline needs to be unscrewed from the old unit. No reprogramming or similar needed.

[Scrump]

Cant help with the cost as I had mine replaced under warranty. It seems to be a common failure on the E class estates, surprised the air suspension units have such a short lifespan.

[Candellara]

Thanks

I'll get a price on the dealer items but also aftermarket as well.

Think it's a DIY job

[Candellara]

Update on this.

Now the weather has warmed up a bit - the rear suspension doesn't seem to drop overnight.

I replaced the valve block that is located just behind the rear bumper - just really to rule that part out. Made no difference.

We've checked all the pipework for any obvious leaks but there doesn't seem to be any. So, finally before we change the rear air bellows, I've one last thought.

There must be a valve that releases air from the system. For example, if I load the car up with loads of heavy items in the boot, drive and then off load the items - you can then hear air being let out to re-level the rear suspension.

Whereabouts is this air released from? Must be a centrally located valve that brings both the OS and NS down. My thoughts are that if this valve isn't sealing shut correctly - it's leaking air from the rear suspension - maybe a weak o-ring that contracts and leaks when the temp is cold?

Logical?

[AC43]

Candellara said:

Update on this.

Now the weather has warmed up a bit - the rear suspension doesn't seem to drop overnight.

I replaced the valve block that is located just behind the rear bumper - just really to rule that part out. Made no difference.

We've checked all the pipework for any obvious leaks but there doesn't seem to be any. So, finally before we change the rear air bellows, I've one last thought.

There must be a valve that releases air from the system. For example, if I load the car up with loads of heavy items in the boot, drive and then off load the items - you can then hear air being let out to re-level the rear suspension.

Whereabouts is this air released from? Must be a centrally located valve that brings both the OS and NS down. My thoughts are that if this valve isn't sealing shut correctly - it's leaking air from the rear suspension - maybe a weak o-ring that contracts and leaks when the temp is cold?

Logical?

I have a small leak in mine. It's a full Airmatic set up so don't know if it's exactly the same as yours but my indy couldn't find a leak anywhere exposed with soapy water or whatever so their theory is therefore that it's more likely to be one of the air springs than anything else. Aparrently it's quite common to get a bit of debris lodged in them which then creates a tiny pin-prick hole.

In this weather it's barely noticeable but when it was really cold it went down quicker.

Once things get better I'll get a couple of Arnott's for £300-ish ea and get them fitted.

[Candellara]

AC43 said:

I have a small leak in mine. It's a full Airmatic set up so don't know if it's exactly the same as yours but my indy couldn't find a leak anywhere exposed with soapy water or whatever so their theory is therefore that it's more likely to be one of the air springs than anything else. Aparrently it's quite common to get a bit of debris lodged in them which then creates a tiny pin-prick hole.

In this weather it's barely noticeable but when it was really cold it went down quicker.

Once things get better I'll get a couple of Arnott's for £300-ish ea and get them fitted.

Being an estate (so an S212 not a W212) it's just airmatic rear. So my thoughts remain, before we pull the trigger on a £1200 rear air bellow replacement - where is the valve located that drops air out of the system? My thoughts are that this could be the culprit as during very cold weather, there isn't one side that drops - it drops uniformly across the rear

[lemonslap]

Candellara said:

AC43 said:

I have a small leak in mine. It's a full Airmatic set up so don't know if it's exactly the same as yours but my indy couldn't find a leak anywhere exposed with soapy water or whatever so their theory is therefore that it's more likely to be one of the air springs than anything else. Aparrently it's quite common to get a bit of debris lodged in them which then creates a tiny pin-prick hole.

In this weather it's barely noticeable but when it was really cold it went down quicker.

Once things get better I'll get a couple of Arnott's for £300-ish ea and get them fitted.

Being an estate (so an S212 not a W212) it's just airmatic rear. So my thoughts remain, before we pull the trigger on a £1200 rear air bellow replacement - where is the valve located that drops air out of the system? My thoughts are that this could be the culprit as during very cold weather, there isn't one side that drops - it drops uniformly across the rear

On my S211 the pressure release valve is built into the pump, don’t know if it’s the same on the S212.

[Candellara]

lemonslap said:

On my S211 the pressure release valve is built into the pump, don’t know if it’s the same on the S212.

That helps. Thanks

[softtop]

I have heard that you can remove it all and go back to standard suspension. After spending about £2,000 replacing parts I sold it on to someone who was planning that change.

[AC43]

softtop said:

I have heard that you can remove it all and go back to standard suspension. After spending about £2,000 replacing parts I sold it on to someone who was planning that change.

I wouldn't bother myself as the Merc Airmatic set up seems way more reliable than the equivalents from, say Audi & LR and is brilliant in terms of comfort, body control and noise supression.

Yes, the struts at the front and springs/dampers at the back are more expensive than convention items but the springs and dampers are all active units.

I ran my last E Class to 145k and the only problem I had was with the pump but on those miles, that's fair enough. On this one I suspect it's one of the rear units (it drops slightly on one side). I don't mind freshening it up with some new Arnotts as I'd probably do a suspension refresh anyway on any car as it hits 10 years and the miles start climbing.

So the additional cost of the Air set up doesn't seem so bad to me, anyway. Helped by the fact that it's a great set up.