Airmatic: a little different problem

Dec 20, 2010 | 10:23 AM

Robbie3015

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2004 E500

Airmatic: a little different problem

On my 2004 E500 I have a little issue with the Airmatic. It intermittently fails to keep the car aired up. I don't think I have a leak, because there are times that the car is sitting low the next morning, but there are also times that I have it parked at the airport for 4 to 5 days and it still sits at the right level. It is always the back, never the front. I had the diagnostics run at the dealership and they said no faults or warnings came back. The equipment under the rear axle looks in very good shape, the aluminum regulator boxes still have somewhat of a shine to it and there are no tears in the rubber sleeve. A buddy of mine suggested maybe a sticky valve somewhere in the system and if I would put maybe a few drops of airtool lubricant in it and maybe blow the system off, that might do the trick. I have worked with 18-wheeler tractors and they usually have a canister that holds an antifreeze / lubricant mixture and it would be something like that. However, I am kind of hesitant. First, I do not know where I can open the system to put some lubricant in and secondly I have seen in the past that chemicals that work in every other car suddenly have side effects in an MB. On top of that it might not even be the problem. When the car runs, the compressor kicks in regularly, usually after braking, but not excessively. Maybe the switch is sticky or it has a battery saving program in it. I don't know! Anybody has seen something similar? Any advice is welcome.

Dec 20, 2010 | 11:51 AM

Diesel Benz

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223.168 & 213.012 & 906.633 & 214.005

Have you noticed if the rear drops specifically at cold temperatures? I don't know why this seems to be a common issue, I assume it must be the valves at the struts randomly not closing properly when the car is parked.

The compressor you hear is most likely the SBC pump. It is difficult to hear the Airmatic compressor during driving, even when steady.

The compressor has a drier built in, it should not need any antifreeze (modern trucks don't either). It would be difficult to feed it in, not sure if it would do more harm than help.

Jan 3, 2011 | 09:15 AM

OK55

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Mercedes E55 AMG (2006), Mercedes 560 SEL (1991)

Most likely you've got a slow leak in the rear somewhere. Could be a hose or connector or could be an air strut. You'll have to do some patient troubleshooting to locate the source. Alternatively, you could use it a while longer - the leak eventually gets more pronounced and shows itself.
Brgds

Jan 4, 2011 | 12:36 AM

zszalay

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05 E500 4M

Very likely this is the problem :

http://www.benzworld.org/forums/w211...ic-spring.html

Jan 4, 2011 | 10:56 AM

starbrite

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2004 E320

Good link zz and you're probably right.

Jan 4, 2011 | 07:58 PM

vettdvr

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03 E500 and Corvette

I had the same problem in my 2003 E500. I found a leaky airbag spring. The fold will seal the leak and as the temp drops for the parked car the leak will open in the fold and cause it to leak more. I give you 95% probability of leaky air spring. Replace both, I did at 80,000 miles.

Jan 5, 2011 | 04:09 AM

Diesel Benz

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Quote:

Originally Posted by vettdvr

This could well explain why the car sometimes stays up for several days and sometimes dose not. A leak in the pipes/connectors should more likely be present all the time.

The valves a the struts do let air out at extreme cold (every now and then) even if all parts were good (as good as they can be).