kp89gt

On my last 2 road trips, I've gotten the dreaded "visit workshop" airmatic warning.

I never noticed anything wrong, until yesterday when the rear was slammed.

The first time it was 3 hours into a highway drive. Never noticed anything and it never threw a code again.

Did it twice this week, once after an hour, and another time after 2 hours.

When I stopped to fill up, I noticed the rear dropped. Started it up, got the "stop too low" message. Tried to raise it manually, which just threw a code again. Shut the car off, started it back up and the rear rose up to ride height.

I read through a ton of posts, but not clear on what it might be. I am suspecting the relay, since after restarting it a couple of times, it came back up.

Car is new to me, but has 67,000 miles on it. From the records, I think it sat a lot (there's a trickle charger on the battery too). I've never seen any corner drop, so I think the struts are NOT leaking.

I am supposed to get my STAR unit tomorrow, so I will pull the codes and post them.

Thoughts?

zarevron

Aluminum Bladders likely have pinhole leaks in them - they can be spot welded and repaired. With that said, it could be other things obviously - but 3 out of 4 times that was my issue. Since having that fixed I don't get any drop, even when parked for the winter. Worth checking out and a cheap fix if that is your issue.

austingtir

^^^ This man speaks the truth.

Since I replaced my rears with arnotts which removed the aluminium tank my car stays up even for weeks on end it never seems to drop at all.

I bet a large majority of issues are caused by those leaky tanks.

kp89gt

Thanks!

I'll check it out. Are the pinholes visible, or should I do a dunk test?

zarevron

Well I've held mine in my hand and didn't see holes when in actuality it was leaking badly. So yeah dunk might be advisable.

bbirdwell

Spray with soapy water at the hose connections to the tanks and the shocks. If it is leaking, you'll see it.
http://www.benzworld.org/forums/w211...l#post11231034

kp89gt

This looks like a likely culprit, so, I'm going to try that first.

I pulled the codes with my new STAR system and I get the 2 generic codes

5503 recovery time during filling of central reservoir too long
5508 the pressure line system leaks

I did a test on the reservoir filing, and it passed, but it took a little bit to get from 13 bar to 14 bar.

I think I've got a small leak in the right rear.

Is there a test that can be run for each corner?

austingtir

I think it'd be good to have an airmatic dedicated sticky to put all these common faults and fixes into one thread?

I thought I knew most stuff about it but didnt know about this replacement piston ring for the compressor for instance.....

kp89gt

I soaped up all the connections in the rear (line to bellows, line out of airbag, and distribution tree), but couldn't find any leaks.

Of course, it was 50 here, and I've only had issues when it's been below 20 degrees.

I think this is a wait and see at this point. I did learn some more stuff about airmatic. There is apparently a solenoid that turns off the bellows when in either of the Sport modes. As an experiment, I figure I could shut off Comfort mode to see if it's the bellows.

I also saw another post where moisture could build up and freeze the solenoid. I'me thinking this may be an area to focus on, since I've only had issues below freezing.

bbirdwell

The solenoids to the external tank are disengaged when the car is turned off. i.e. even if you have the car in Sport 1 or Sport 2 mode, as soon as you kill power, the solenoids (Y53/1y1 and Y54/1y1) open to the external tank and, if the leak is external to the air shock, the car will sag.


An alternative option to check the connections to the external volume tanks is to leave the car running (power on to energize the solenoids while in Sport 1 or Sport 2 mode) when you stop for whatever reason. If the car does not sag, that "suggests" the leak is in the connection to the external volume tanks OR there is another leak in the system small enough (for now) that the air pump can stay ahead of the leak. If the car does sag while the car is running or powered up, it suggests a large leak elsewhere (but at the potential cost of burning out your air pump). Additional course of action: start car, allow suspension to inflate, pull fuse to air pump, see if car sags after stop but with/without power (i.e. Comfort mode vs Sport mode) on to the rear solenoids.


Hope this gives you some ideas....


When you get this fixed, please update this thread for future inquiries.