MJBelcher500

The car currently has 144k miles. It is a California car with no rust or corrosion and in very good mechanical condition (properly maintained throughout its life)

I had noticed that the car would start to sag at the rear if parked for several days. While the front struts had been replaced with Arnott, the rear still had the original air springs. I drive this car long distances and didn't want to risk a blowout, so I recently replace the rear springs with Arnott as well (A2725) and replaced the shocks (OEM Bilstein) at the same time. As an aside, the car rides much better now.

Sadly, I the rear still sags if parked for a few days. No issues at the front. I had not found any leaks from the lines at the back or at the reservoir tank. I suspect it might be the distribution valve above the compressor (211-320-01-58). My understanding is that the valve seats can intermittently stick causing air loss. Any thoughts as to other areas I might check before ordering the valve?

machild

The distribution valve is a maintenance item. Replace it due to its age and then see where things stand.

MJBelcher500

Thank you sir! That is what I was thinking.

Yuille36

These airline valve blocks due tend to leak as they age.

Rafichicago

My advise is eliminate guesswork.
lift the car remove the wheels and spray water with soap look for air bubbles. I’ve just replaced rear bags on 04 E320. The car would lift with original bags but would sag after day or two. Airmatic compressor was noisy as well. After rear airbag replacement car wouldn’t raise at all. It took a new compressor for it to function properly. I’ve replaced rear bags with the ones that allow for rear center air reservoir to be disconnected. If you don’t work on your own car take it somewhere and have it properly diagnosed before randomly throwing parts at it.

MJBelcher500

I do all my own work. It doesn't really make sense to have one of these cars and pay someone else to work on it (not for me, anyway). As mentioned, I wanted to replace the air springs (Arnott without the reservoirs) anyway due to age/mileage and due to my driving hundreds of miles at a time.

The only item I haven't replaced at this point is the distribution valve. At only $200, I am just going to replace it since it is 16 years only and not that big of a job. If that doesn't resolve it then it is a leaking line somewhere. I''' look for that while I have it on the lift to do the valve.

Rafichicago

The only item I haven't replaced at this point is the distribution valve. At only $200, I am just going to replace it since it is 16 years only and not that big of a job. If that doesn't resolve it then it is a leaking line somewhere. I''' look for that while I have it on the lift to do the valve.[/QUOTE]

Make sure that you buy original one. This part as well as aftermarket front struts are not the greatest and cause problems. Replace once pay once and forget. Good luck👍

MJBelcher500

Make sure that you buy original one. This part as well as aftermarket front struts are not the greatest and cause problems. Replace once pay once and forget. Good luck👍[/QUOTE]

Yes, I purchased the factory BM part, This is not an item I was willing to risk using an aftermarket part on. I'll report back with my findings.

MJBelcher500

I am getting ready to replace the airmatic distribution valve and have a quick question for those of you that have done it. Does the car need to be on a lift to replace? I did a bit of searching, but cannot tell if the block is pressurized and the suspension will lower if disconnected. It seems like the air springs/struts should maintain their pressure with it disconnected, but I wanted to confirm one way or the other. I have a lift, but its a bit of a hassle if not needed.

Yuille36

The car doesn't need to be on a lift, but the front needs to be supporting on jack stands. As you'll need to remove the wheels and fender liners to get access to the distribution valve, which is located above the air compressor.

MJBelcher500

Yullie, you are saying that just the one corner needs to be supported to remove the wheel? Air is retained in the springs with the valve removed?

Yuille36

To replace the air distribution valve, the driver's side wheel needs to be removed, so the car needs to be supported with a floor jack. The fender liner needs to be removed to give you access to the distribution valve.
The air should be retained in the air struts and the air springs, when the lines are disconnected. Remember that the air-struts have electrical connections to them, that controls the valve to let air in or out.
So, the entire car doesn't need to be lifted, if you're working in a garage without a lift. Once, you install the new valve and the car is resting on its wheels once again, cycle the suspension up and down with the button below the shifter.

MJBelcher500

Thank you! This is what I thought, but I feel better with your confirmation.

Yuille36

If air does leak out, it's no biggie. As soon as you got everything back together, your air compressor will re-pressurize the air tank in the trunk, and the airmatic will re-level the suspension.

MJBelcher500

I was more concerned about the suspension completely deflating, which I would try to avoid.

MJBelcher500

Just wanted to follow up. I replaced the distribution valve last night. No issues and the suspension did not deflate. The reservoir in the truck did empty however. Easy enough job. Thanks for everyone's input on this.

Yuille36

I'm glad that everything worked out for you. And if your suspension had deflated, it would re-inflate once air pressure had built up.
The airmatic is a pretty smart system, if everything is working properly.

MJBelcher500

Thanks Yuille.

My understanding is that it isn't a good idea to have the full vehicle weight on deflated suspension. I cannot imagine it is good for the springs or front struts.

Yuille36

And you would be correct, especially if the air springs and air struts are old, as the rubber membranes get brittle and developed cracks. Which lead to air leaks. So how long did the actual install take you?

MJBelcher500

I worked slowly and it took me about an hour. I did the valve and replaced the compressor while I was in there.

Yuille36

That was smart to replace the air compressor while you were in there. After, I replaced my compressor, the car aired up so much quicker.

MJBelcher500

I had already replaced the piston ring in the original compressor and it was working fine. There were a couple of rough spots at the top of the cylinder bore (compressor) that look like water had gotten in there and corroded it. Still, it was working fine.

Since I do a lot of long distance driving I decided to just replace everything and not worry about it for quite some time. At this point, everything in the Airmatic system except the plastic lines and the trunk reservoir have been replaced. Fingers crossed, it should be good to go.

Currently, I have proactively replaced all of the known " failure parts" before they fail (conductor plate, Airmatic, voltage regulator, intercooler pump, harmonic damper, CPS, etc.) The car seems pretty happy at the moment :-)

Yuille36

This is good to hear, we both have a similar ideology, replace it before it fails. I too have replaced airmatic components, head bolts, lifters, coolant reservoir and the entire suspension on my E63. There has been so much work done on my car, that my girlfriend says that my car knows when it payday. 😁 And I tell her it’s preventative maintenance 👍🏽

nd-photo.nl

Good strategy @MJBelcher500 , Im currently in the process of doing that as well. See my build thread here: https://mbworld.org/forums/c219/8443...ld-thread.html

MJBelcher500

I thought I would post an update on this.

I replaced the Airmatic distribution valve with MB part number 2113200158 as well as the Airmatic compressor MB part number 3113200304 (original pump, not a Chinese copy). Both of these were purchased well under retail. The valve was $200 (purchased from an online MB Dealer) and the compressor was $275 (FCP Euro was having a sale on the compressors).

After parking the car for 5 days there has not been any sagging at the rear. Previously, it would have been noticeably lower by now. I will keep monitoring it, but I am hopeful the issue is resolved.