14 e550 rear air bags deflate after few hrs - replaced air solenoid block
This morning, again. Rear airbags were deflated.
I've owned the car a week and it's both of them together, ones not higher or lower, I don't suspect a leaking air bag/s.
Any thoughts on further diag and direction? Thinking what are the odds of it doing the same thing with a new block. Doubt somehow the cars computer is doing it?
EDIT/UPDATE: It was both rear airbags.
Last edited by Octan3; Jul 9, 2023 at 01:06 PM.




There are hoses/connections for:
1 - Front air bags (if present)
2 - Rear air bags
3 - Reserve tank
4 - T-splitter at the back, see over the rear subframe
Anywhere there is a connection, there is a chance for a leak. Since both are deflating, I would definitely check the T-splitter.
Though not for your specific vehicle, here is someone's else summary for the W220 platform. The important part is the line of thought used to solve problems.
Last edited by JCM_MB; Jun 16, 2023 at 01:30 PM.
There are hoses/connections for:
1 - Front air bags (if present)
2 - Rear air bags
3 - Reserve tank
4 - T-splitter at the back, see over the rear subframe
Anywhere there is a connection, there is a chance for a leak. Since both are deflating, I would definitely check the T-splitter.
Though not for your specific vehicle, here is someone's else summary for the W220 platform. The important part is the line of thought used to solve problems.




But the common principle is soapy water and search for connections. Sometimes is at the top of the airbag where the hose comes in; however, for both to deflate both have to be damaged.. Unlikely in common situations, but possible.
If it was the compressor you can usually hear it while it's on its last legs. Compressors tend to die prematurely when they have electrical faults, or they've been operating for so long trying to fill bags up that they physically melt. Then you'd be able to find this via Xentry. Mercedes dealer likes to sell them together as a unit cuz well, money but I seldom in my professional experience have to replace the pump and valve block.
Alpha European Autotech
Purchase Amsoil at 25% off from me
Chris Tran, Retired Alpha European Autotech Owner
Amsoil Independent Dealer #7236674
the previous owner will tell me the dealership changed the battery and i'm looking at a 12 year old battery that stranded them every. single. time. another hilarious one is that they "just had the oil changed the other day" and the engine cooked off a full quart of sooty used oil, and their filter is crushed to bejeezus when i remove it so it'd been in there a while, and it is very, very difficult to crush a Mann filter.
the sooner you take over repairs for the car, the sooner you can enjoy the pleasantries of mercedes ownership. I have a huge soft spot for E550's. They practically cost as-much as AMG cars but have nicer interiors, comfort, and are easier to live with mechanically since they often share parts with the 350 series of cars.
Alpha European Autotech
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Chris Tran, Retired Alpha European Autotech Owner
Amsoil Independent Dealer #7236674
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A lil update: I Clamped off/blocked the air lines not far up from the air solenoid which would then completely isolate the bags from it. (I should of done that first) and they both deflated over night still, deff an issue upstream. I did a quick visual on the airbag lines and did not see any sort of T, appears like a direct run from airbag to the solenoid though they run under some of the exhaust heat shielding. This evening I will plan to spray it with soapy water every where.
The Best of Mercedes & AMG
Another update: Last night I Sprayed the lines down and the airbag fittings with very soapy water, could not see any leaks, I really paid close attention to the fittings into the air bags, again no air leaks. I clamped the lines again just before the airbags. Unfortunately they still deflated, Looks like I need 2 rear airbags.
Car only has 59k miles on her lol.




Here the listing I bought from
https://www.ebay.ca/itm/Pair-Rear-Le...-127632-2357-0




This morning, again. Rear airbags were deflated.
I've owned the car a week and it's both of them together, ones not higher or lower, I don't suspect a leaking air bag/s.
Any thoughts on further diag and direction? Thinking what are the odds of it doing the same thing with a new block. Doubt somehow the cars computer is doing it?
In my car it caused a bit of confusion as sometimes rear of the car was all the way down but then at times it was not. I found out it depends on what height I left the car when I parked it. In SPORTS it went all the way down both side but in COMFORT it did not, just left side was all the way down but the right side was up some.
I think this behavior comes from the fact that in COMFORT mode springs are high enough to develop enough pressure in just one spring to keep the rear of the car from going all the way down when with SPORTS setting springs are too short for this and both sides go all the way down.
I think you have a leaking spring.
In my car it caused a bit of confusion as sometimes rear of the car was all the way down but then at times it was not. I found out it depends on what height I left the car when I parked it. In SPORTS it went all the way down both side but in COMFORT it did not, just left side was all the way down but the right side was up some.
I think this behavior comes from the fact that in COMFORT mode springs are high enough to develop enough pressure in just one spring to keep the rear of the car from going all the way down when with SPORTS setting springs are too short for this and both sides go all the way down.
I think you have a leaking spring.
The bags finally came in and I installed them last night. For the most part they were identical but the bottoms that go into the control arm was a bit different, all the youtube videos showed the factory ones had that ribbed moulded plastic maybe an updated design? however my factory ones had the plastic moulded smooth bottoms, these ones had the plastic ribbed bottoms. However the circular base that sits into the lower control arm was the same size there for its centered and wont move anyways.
So long short of that is they're fine.
Replaced them last night, quick drive then parked the car in the garage, came in this morning and they did NOT deflate... Yay... I'd say that's a battle won, Time will tell how long they last. I see no reason why they shouldn't last another 60k miles. a few people on FB have had them for years with no issues and mentioend they were identical to the arnotts anyways so who knows.




The bags finally came in and I installed them last night. For the most part they were identical but the bottoms that go into the control arm was a bit different, all the youtube videos showed the factory ones had that ribbed moulded plastic maybe an updated design? however my factory ones had the plastic moulded smooth bottoms, these ones had the plastic ribbed bottoms. However the circular base that sits into the lower control arm was the same size there for its centered and wont move anyways.
So long short of that is they're fine.
Replaced them last night, quick drive then parked the car in the garage, came in this morning and they did NOT deflate... Yay... I'd say that's a battle won, Time will tell how long they last. I see no reason why they shouldn't last another 60k miles. a few people on FB have had them for years with no issues and mentioend they were identical to the arnotts anyways so who knows.
Our E-class is not that bad for the leak as you can drive the car with leaking spring. You just see the car down in the mornings, but it raises back up when you start it up. My S-class is different. I got a leak in front and the car dropped down and did not come back up. Hard to drive car like that but I did for 350 miles to get it home for repairs.
Our E-class is not that bad for the leak as you can drive the car with leaking spring. You just see the car down in the mornings, but it raises back up when you start it up. My S-class is different. I got a leak in front and the car dropped down and did not come back up. Hard to drive car like that but I did for 350 miles to get it home for repairs.
Yeah I mean your not wrong on the age idea and the fronts, but if they did start to leak it'll be a small leak very likely like the rears, and yeah eventually rhe computer throws the fault and no longer bothers to air up, I had to clear the code 3 times or so the past few weeks to Driving it. I'll end up holding off and review it next summer,




But the common principle is soapy water and search for connections. Sometimes is at the top of the airbag where the hose comes in; however, for both to deflate both have to be damaged.. Unlikely in common situations, but possible.




In my car it caused a bit of confusion as sometimes rear of the car was all the way down but then at times it was not. I found out it depends on what height I left the car when I parked it. In SPORTS it went all the way down both side but in COMFORT it did not, just left side was all the way down but the right side was up some.
I think this behavior comes from the fact that in COMFORT mode springs are high enough to develop enough pressure in just one spring to keep the rear of the car from going all the way down when with SPORTS setting springs are too short for this and both sides go all the way down.
I think you have a leaking spring.


