dexter_morgan

Hi,

My 2012 E550 is 10 years old but only has 55K. Today morning I noticed that rear right was sunken. I did not use it 2 days in a row and found sunken. Is it normal to have faulty spring at just 55K. Compressor is good.

kajtek1

Air bags are rubber, just like tires.
Regardless of the mileage, you should replace them every few years.
At 11 years you've got your money worth.

KEY08

Yes, they aged out

up_too_late

I recently replaced mine, 2015 with 60,000 miles.

dexter_morgan

Is Arnott good to replace OE one? Any experience?

MBENZTECH

Anything Arnott sells, is perfect. I use them all day long at my shop. One thing to note about W212's is that the valve block assembly tends to build up corrosion on the valves, causing the struts to leak.

dexter_morgan

Is it possible to check/clean valve block assembly? Is it located in passenger side wheel well?

KEY08

I believe it is under trunk if you get down there and look around. That’s just from memory and owning a couple Airmatic optioned MB’s.

dexter_morgan

Thank you. Is it possible to clean valve block assembly if it is corroded?

Fliplegend

The general recommendation is to spray soapy water on the connections to see if air is leaking from any of them.

konigstiger

See attachments.

cvx5832

Mine started leaking at around 58k. Arnott units were/are perfect, even felt smoother owing to the fresh bag rubber. That said I couldn't find where it was leaking, granted it may be as small as a pin hole, but my theory is on the VOSS fitting to the bag. Those can be had for cheap so if you don't mind the project you can try replacing that first. Or spray it to see if there's bubbles coming out.

up_too_late

I was in the same position of questioning to replace the air springs or spend time trying to find exactly where the leak was. My thought was that if I'm going to spend hours under the car it might as well be to replace the most suspect parts, especially when that part is known to be an age limited component. At worst I figured I would be doing preventative maintenance. From my perspective it seems the vast majority on this forum (and youtube for that matter) have found the issue has been aging air springs. I have only seen one or two on here with an abraded airline that they found with soapy water. I didn't want to waste a bunch of time doing the "easy stuff" only to have to do the air springs anyway. It turned out to be a lot easier than I had anticipated.

My car has been sitting at least the last 5 days without being driven and hasn't sunk at all, so I'm fairly confident it was an air spring. I have not dissected the old ones yet to see what they looked like under the protective covers.

I see the OP is in Canada, you might want to replace the bags just for the reason they are only going to get harder to get out as time goes on due to salt and rust.

Luddyludwick

OP, did you get this fixed? Mine has been an issue on-and-off for about six months now. I'm pretty sure the issue is the valve block in my case. At times, I can park it for a week (I don't always DD it) and the bags will hold. At other times, it's a few hours. I need to replace it soon since (of course) I don't want the pump to die. Might be worth checking.

AllPhonesAretap

Just about right on time @ half the life of a regular shock (by Mercedes Benz at least)

Popell996

My S212 E350CGI is approaching 118k miles, rear started dropping intermittently.
weirdly, it could stay up all night(!) and would be up when I look out of the window, then be on its haunches by the time I’ve finished breakfast-without me touching the car, nor unlocking it or anything!

on other occasions, with the rear door up, suspension at normal level, I can sit on the load floor checking my phone or whatever and I can feel the car lowering! Even if it’s been a couple of hours since switch off!

it went from normal to full drop in the time it took me to collect fish and chips last week

it has always seemed to be a little low on lhs and certainly when it drops it goes left first.

im happy to replace bags or the valve block but would appreciate comments or steers in the right direction please.

also, recommendations for sourcing parts…
thanks in advance

kajtek1

Finding small air bubbles on bags, who not only have dual chambers, but have multi-folds under the covers proved to be next to impossible.
What you can always do is to get a scanner, who can activate the pump and go under the car with spray bottle of soapy water.
That would eliminate piping and valves failure.
Still if the car drop happens only on some occasions is big indication of leak on bags, where folds can hold it more or less depends how it stops.
Piping leaks usually are consistent.
Lastly if your bags are 10 yo, you've got your money worth and just replace them.

Aussie_E350_Wag

My 14 E350 wagon did exactly that, bought 2 new bags off eBay and she's sweet as, 2 weeks sitting and hasn't moved at all, rides firmer in the **** end now too,

Popell996

Thanks for the reply Kajtek, thought/suspected it would be this. Guess I’ll be ordering a pair of bags…
would just hate it if the valve block was the eventual culprit but on balance of probabilities, likely to be the bags.

Popell996

Thanks for taking the time I reply Aussie, which bags did you go for? Any big difficulty fitting them?

Aussie_E350_Wag

No it's super easy, I could be wrong but the wagons are a little bit different in their control arms as I only undid 3 bolts, bottom shock bolt included and with a pry bar they came out very easy.

*Note I have a hoist/lift in a workshop to use so that is a massive advantage.

To be honest I paid $99.00 for a pair off eBay vs. $600 each for Arnotts as the shipping even on RockAuto is was pretty scary to Australia.

If I get 3-5yrs outta them I'm happy as it's 30-40 job to swap out new ones.

Popell996

Thanks, I’m thinking along the same lines, cars nice but not worth pushing too much cash into it if it lasts three or four years it will be good enough for me.