More Airmatic Drama
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
More Airmatic Drama
In all fairness I have not taken it to a specialist. Just trying to pick your minds what you guys think could be the issue from your personal experience. I've dealt with Airmatic issues before. Once was a blown rear bag. The other was a rear leveling sensor. In both cases this threw the driving experience and suspension out of whack.
This time it's different. When driving all is normal. No issues. However here is what I have observed.
1) When parked overnight or sometimes for an hour the entire front sags.
2) 2/10 times even overnight all seems good and no sagging when I walk out to the ML the next morning.
3) I hear every 2-5 mins from the front a pressure release of air while driving. I assume the compressor is trying to compensate but truthfully I don't hear the compressor while driving. Just the blowoff release every 2-5 mins.
Has anyone had a similar experience?
Here is what I'm thinking.
1) Leaking or faulty Valve Box located in the front passenger fender.
2) A leak in one of the front lines.
3) One of the front bags are leaking. Most likely the driver side cause when this all started only the front driver side was squatting.
Any thoughts would be greatly appreciated. Take care team.
This time it's different. When driving all is normal. No issues. However here is what I have observed.
1) When parked overnight or sometimes for an hour the entire front sags.
2) 2/10 times even overnight all seems good and no sagging when I walk out to the ML the next morning.
3) I hear every 2-5 mins from the front a pressure release of air while driving. I assume the compressor is trying to compensate but truthfully I don't hear the compressor while driving. Just the blowoff release every 2-5 mins.
Has anyone had a similar experience?
Here is what I'm thinking.
1) Leaking or faulty Valve Box located in the front passenger fender.
2) A leak in one of the front lines.
3) One of the front bags are leaking. Most likely the driver side cause when this all started only the front driver side was squatting.
Any thoughts would be greatly appreciated. Take care team.
Super Member
Joined: Nov 2017
Posts: 558
Likes: 114
From: San Francisco Bay Area
2006 R500
Had a front bag leak on my R500 that had similar issues. In normal height, the hole was in an area where the bag was folded over itself so it basically sealed itself shut, having a very slow leak that only was visible after a week of being parked. Over time that hole got bigger until it got to the point where when the car lowered itself at highway speeds, the leak was greater than what the air compressor could supply and I got the Airmatic faults. Pulled over and the car was incapable of rising. Decided to just drive it back as is, and as I pulled out of the gas station the suspension aligned itself just right to shut the hole again, allowing it to rise back up until it again lowered itself at highway speeds.
A good test would be to use the raise function, raising the car to its maximum height to take out all of the folds. If there is a leak in the front bag, it should be pretty easy to catch.
A good test would be to use the raise function, raising the car to its maximum height to take out all of the folds. If there is a leak in the front bag, it should be pretty easy to catch.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
Had a front bag leak on my R500 that had similar issues. In normal height, the hole was in an area where the bag was folded over itself so it basically sealed itself shut, having a very slow leak that only was visible after a week of being parked. Over time that hole got bigger until it got to the point where when the car lowered itself at highway speeds, the leak was greater than what the air compressor could supply and I got the Airmatic faults. Pulled over and the car was incapable of rising. Decided to just drive it back as is, and as I pulled out of the gas station the suspension aligned itself just right to shut the hole again, allowing it to rise back up until it again lowered itself at highway speeds.
A good test would be to use the raise function, raising the car to its maximum height to take out all of the folds. If there is a leak in the front bag, it should be pretty easy to catch.
A good test would be to use the raise function, raising the car to its maximum height to take out all of the folds. If there is a leak in the front bag, it should be pretty easy to catch.
Last edited by OUZO Power; May 21, 2025 at 02:47 PM.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
MBWorld Fanatic!
Joined: Jun 2014
Posts: 1,085
Likes: 442
From: Melbourne, Australia
2010 ML550 VIN WDC1641722A564750, 2010 B180
The soapy water test is only effective if you have the car at its highest setting and sitting on its own weight. That applies to all components so they are fully pressurised. Id say your problem is the valve block. Be careful buying this as arnott make 2 versions- 1 made in China and 1 in the US. Buy the later
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Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
The soapy water test is only effective if you have the car at its highest setting and sitting on its own weight. That applies to all components so they are fully pressurised. Id say your problem is the valve block. Be careful buying this as arnott make 2 versions- 1 made in China and 1 in the US. Buy the later
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Senior Member
Joined: Oct 2023
Posts: 472
Likes: 239
From: New Hampshire
ML 63 AMG
Originally Posted by OUZO Power;[url=tel:9184290
9184290[/url]]Offffff, This was not a cheap fix boys.
1) 3 shocks and bags
2) Compressor
3) Valve Block
4) Rear ride height sensor
1) 3 shocks and bags
2) Compressor
3) Valve Block
4) Rear ride height sensor
In all seriousness sorry to hear to hear about all those airmatic components needing replacement… ouch.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
Well that was short lived. 2 months passed and the entire car is squatting. Malfunction warning on the dash and the new compressor is definitely not kicking in.
Senior Member
Joined: Apr 2007
Posts: 432
Likes: 79
Former R230, W220 and W221 owner
I was filled with joy when I found out you can get the ML with standard shocks/springs. It was the selling point when searching for a luxury SUV. Soon as I found an SUV I liked and saw air strut, I ran away faster than usain bolt.
With that said, did the mechanic use an OEM compressor? I learned the hard way that these cars don't like aftermarket air suspension/ABC parts.
Last edited by imtheking; Sep 23, 2025 at 10:46 AM.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
Airmatic/ABC suspension issues. I don't miss those days at all. No matter how much preventive maintenance I did on my S and SL class, some random suspension issue always came up and at a very high cost.
I was filled with joy when I found out you can get the ML with standard shocks/springs. It was the selling point when searching for a luxury SUV. Soon as I found an SUV I liked and saw air strut, I ran away faster than usain bolt.
With that said, did the mechanic use an OEM compressor? I learned the hard way that these cars don't like aftermarket air suspension/ABC parts.
I was filled with joy when I found out you can get the ML with standard shocks/springs. It was the selling point when searching for a luxury SUV. Soon as I found an SUV I liked and saw air strut, I ran away faster than usain bolt.
With that said, did the mechanic use an OEM compressor? I learned the hard way that these cars don't like aftermarket air suspension/ABC parts.
Super Member
Joined: Jan 2007
Posts: 622
Likes: 202
From: CA
11 ML550, 95 Supra TT, 14 Audi S4
Airmatic/ABC suspension issues. I don't miss those days at all. No matter how much preventive maintenance I did on my S and SL class, some random suspension issue always came up and at a very high cost.
I was filled with joy when I found out you can get the ML with standard shocks/springs. It was the selling point when searching for a luxury SUV. Soon as I found an SUV I liked and saw air strut, I ran away faster than usain bolt.
With that said, did the mechanic use an OEM compressor? I learned the hard way that these cars don't like aftermarket air suspension/ABC parts.
I was filled with joy when I found out you can get the ML with standard shocks/springs. It was the selling point when searching for a luxury SUV. Soon as I found an SUV I liked and saw air strut, I ran away faster than usain bolt.
With that said, did the mechanic use an OEM compressor? I learned the hard way that these cars don't like aftermarket air suspension/ABC parts.
Senior Member
Joined: Apr 2007
Posts: 432
Likes: 79
Former R230, W220 and W221 owner
Amen. After 13 years of X164 ownership with airmatic, I don't miss it. When it works properly, it rides/handles better than the conventional suspension (currently have a ML550 with springs), but the endless repairs aren't worth it IMO. Adding up all the things I had to replace, I was averaging more than one repair per year.
If you are a DIY'er it's not that bad. You can bring the cost down a little.....but still.
A bad ABC suspension can leave you stranded. Here you are driving down the street and booom....a hose blows out with fluid all over the place. and if you don't stop, you can destroy your pump. Yuck. Never again.
and yes, I know they have coilover conversions now. I rode in a SL with Strutmaster and it felt like trash.
Last edited by imtheking; Sep 23, 2025 at 02:19 PM.
Super Member
Joined: Jan 2007
Posts: 622
Likes: 202
From: CA
11 ML550, 95 Supra TT, 14 Audi S4
If you thought airmatic was bad, imagine ABC suspension. Pumps, hoses, valve blocks, sensors, accumulators, hydraulic fluid at $30 a quart etc.....absolute nightmare. Never spent less than $1000 on a repair. and the issue wasn't always straight forward. There were times my mechanic had to spend days trying to figure out the issue. Complete headache. He's a master mercedes mechanic and even he hated working on the ABC system.
If you are a DIY'er it's not that bad. You can bring the cost down a little.....but still.
A bad ABC suspension can leave you stranded. Here you are driving down the street and booom....a hose blows out with fluid all over the place. and if you don't stop, you can destroy your pump. Yuck. Never again.
and yes, I know they have coilover conversions now. I rode in a SL with Strutmaster and it felt like trash.
If you are a DIY'er it's not that bad. You can bring the cost down a little.....but still.
A bad ABC suspension can leave you stranded. Here you are driving down the street and booom....a hose blows out with fluid all over the place. and if you don't stop, you can destroy your pump. Yuck. Never again.
and yes, I know they have coilover conversions now. I rode in a SL with Strutmaster and it felt like trash.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 347
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
I lucked out. It was a fuse for the new compressor. Picking it up tomorrow. Have to ask the mechanic now where that fuse is cause chances are it will happen again.
Senior Member
Joined: Oct 2023
Posts: 472
Likes: 239
From: New Hampshire
ML 63 AMG
Originally Posted by OUZO Power;[url=tel:9216535
9216535[/url]]I lucked out. It was a fuse for the new compressor. Picking it up tomorrow. Have to ask the mechanic now where that fuse is cause chances are it will happen again.
Senior Member
Joined: Apr 2007
Posts: 432
Likes: 79
Former R230, W220 and W221 owner
Watching Alex (former master MB tech) struggle with the ABC system on a CL(?) on his LegitStreetCars YouTube channel was enough to convince me I never needed to experience it firsthand. My out of pocket cost on the airmatic wasn't that bad because some of it was fixed under the CPO warranty, and once that ran out, i replaced parts with Arnott, which at the time offered a lifetime warranty on their parts, but the hassle of constantly fixing something got really old. One good thing at least is that the most common failure are the front shocks, which usually slowly fail, so you get plenty of warning that something needs to be fixed. After owning an airmatic car, it is amazing how many older MBs you start noticing driving around and parked with sagging suspensions.
And thank god for Arnott cause the OEM struts were crazy expensive. It helped that at one time they bought back your used struts so you can save a little money. Most people were buying coilovers and selling their struts to arnott. The buy back program usually covered the entire cost of the coilovers. (almost all of it).
It was such as inconvenience. Getting in your car and fearing failure every single time was not how I wanted to live.
Newbie
Joined: Dec 2025
Posts: 12
Likes: 1
2016 Gl 450
Scan tool needed
Hi all,
I am planning to replace front airmatic struts soon, and possibly rear bags along with compressor and valve block. Everything working OK at the moment, but my gl450 is sitting at 10 years old and 90k on the odometer. Front end feels a little underdamped, so I'm thinking those struts are worn. Rear feels OK for now but if I am doing some of the work I might as well replace the aging parts now and hope for a few years without subsequent failures trickling along.
I am trying to avoid the sudden failure and having my wife stranded somewhere with preventive replacement.
Main question is do I need a scan tool to empty and refill the system safely? I have read yes and no, that if you are careful not to loosen the fittings too quickly it can be done safely but mb procedure says to initiate the decompression process via the software...
If so what would be the favorite tool? I see xtool or topdon bidirectional advertising Air suspension functions but I don't want to plunk down another 3-400$ on a tool if not needed or doesn't actually do the job I need it to do. I'm just a home mechanic with two cars so I wouldn't use it much.
Thanks!
I am planning to replace front airmatic struts soon, and possibly rear bags along with compressor and valve block. Everything working OK at the moment, but my gl450 is sitting at 10 years old and 90k on the odometer. Front end feels a little underdamped, so I'm thinking those struts are worn. Rear feels OK for now but if I am doing some of the work I might as well replace the aging parts now and hope for a few years without subsequent failures trickling along.
I am trying to avoid the sudden failure and having my wife stranded somewhere with preventive replacement.
Main question is do I need a scan tool to empty and refill the system safely? I have read yes and no, that if you are careful not to loosen the fittings too quickly it can be done safely but mb procedure says to initiate the decompression process via the software...
If so what would be the favorite tool? I see xtool or topdon bidirectional advertising Air suspension functions but I don't want to plunk down another 3-400$ on a tool if not needed or doesn't actually do the job I need it to do. I'm just a home mechanic with two cars so I wouldn't use it much.
Thanks!
Last edited by Jvac; Feb 7, 2026 at 12:20 PM.
