There is no hydraulic damper inside the airmatic strut. I'm not sure exactly how the internal baffles work, but the system is entirely pneumatic. The adjustability of the dampers is largely due to increasing or decreasing air pressure inside the strut assembly. If you have a strut that is not behaving as it should, it probably has a leak somewhere. Early W220 airmatic suspension systems are well known for their problematic behavior. Your worse case is a strut replacement to the tune of USD1500 or so. There are repair kits available as well for leaks around the fittings at the top of the strut.

Good luck.

 

Thanks for your insight

I have checked for hight differences each night for two months and I do not believe I have any air leaks but I do have a damping problem as you can see from the attachment to my original post. I was thinking of purchasing an Arnott rebuilt strut US$400 but I did not want to do that if the problem somhow lay outside the strut in the stiffness controls. It sounds from your description of how it works that the baffles inside the strut may be damaged ?

Thanks again

PurdieMerc
Sydney Australia

 

I'm sure there is some kind of portioning valve that levels the car and stiffens the inboard struts in corners and so on. It may be that portioning valve or its controller has taken a hike on one strut rather than there being something amiss with the strut itself. I don't know the mechanics of that system, but there are a thousand threads about airmatic on this forum if you do a search. I'm sure you'll come up with a likely cause for your problem.

Cheers.

 

I have the similar problem with harsh ride and vibration, I have no air leaks.I changed the control valve with part 2203200258, 2003 Mercedes-Benz S Class Valve - Parts.com.

The ride is smooth again.

Good luck.

 

was you ride super hard like do not even have a suspension ??? At least that is how my feels I can feel every bump or man hole cover. My old 99 Corola has a much smoother and softer ride. Benz has 18" rims could that be the problem ??? And where did that valve goes to ???

 

Before I change the valve, My car ride like bus, the button on the dash has no difference on the ride, the car feel like no suspension. The control valve
sit on top of the air pump. I has 18" amg wheel on the car. Now it is smooth and soft like before.

 

Here is a picture of the pump can you point where the valve is. Was it hard to install it, like releasing pressure from the system, etc.

 

It is not hard to install. You need to rise the car in all 4 corners, I use jack stand on 4 corners so the car is not put weight on any wheels,remove the air
suspension fuse. When you switch the air tubing from the old valve to the new valve, the air press will released but not much because the jacks. Here is the valve in the picture.

 

is it that whole thing where 5 lines come in ? Looks like mine is very corroded that could be the problem

 

Here is the picture of new one.

 

that would make sense that if a whole car feels like a horse carriage not even close to Camry. Replacing valve system could fix the problems. Just I wonder how hard will it be to take off the fittings since it is so corroded. Was yours so corroded too???

Also maybe that is why I was getting this error, connector could be corroded and not enough voltage is getting to the system.

 

Your error could mean the air suspension relay is bad. Change relay first,see if it solve your problem. For me I changed to new relay twice make no difference.Make sure the electrical connection to the valve is tight.My valve is not corroded.

 

I got one spare relay in the car so will try to replace it. The thing is error have not came back after I erased it, but I know it will. Sometimes out of nothing Airmatic visit workshop comes up and suspension becomes even harder just like there is none, but after restarting the car it is fine

 

Hi All

Thanks for all the input on this problem.

I have now fixed the problem.

I took the car to the stealer and they did some tests and told me I needed to replace the $5600 Airmatic control ECU as it was sending the wrong signals to the hydraulic dampers. I purchased a S/H one and had my mechanic Fit and Code it and the problem has now been fixed.

Regards to all and again
Thanks for all the input.

PurdieMerc
Sydney
Australia

 

"S/H one"?
I am assuming that means an used ECU? And if yes, how much was it compared to the $5600 quoted by the dealer?
You can almost buy another S class with that money

 

i need wiring diagram for valve block, there is 6 pins and i need to know which 2 is for drivers side front shock absorber. mine valve block is leaking in this front shock absorber valve so i connected new single valve for this one shock absorber but i activate this valve by giving it voltage from battery now, and i need these 2 wires from valve block connector to make it automatic...

 

Hi NISMAS,

Did you get a wiring diagram for the valve block? I need it desperately too.

What voltage (12V ??) did you put on which wires to see if the valve is working?

My valve block doesn't let any air through and I replaced it with another one, but still no air coming through. I also replaced the pump, which blows air now into the valve.

I now suspect no power reaching the valve block.

So please help me by giving me a clue on which wires to put a voltage.

Thank you,
Maurice

P.S.: is there also a fuse or relay that could be blown that supplies power to the valve block?

 

Maurice - did you find the fuse details in the W215 stickies (also applicable to W220).

Here: http://www.benzworld.org/forums/w215-cl-class/1599665-w215-fuse-relay-chart.html

From that, I see that Airmatic Control Unit (N51) has 2 fuses. Fuse f9 (30A) is in K40/6 fuse/relay box, and fuse f46 (5A) is in K40/7.

The solenoid valves are not fused - they are driven directly from ACU N51.

I do not have a circuit diagram for W220 N51, but I do have a saved WIS part cct for N51 in a W219 -which might be similar, but please be aware that the fuses for W215 are different to W219. :thumbsup:

 

Hi Keyhole,

Thank you very much. I've checked the fuses and they are good. Hmmmm.

Another peculiar thing I just realised is that relay "O" is not switching on when I start the car and I see the message STOP, car too low.

When I connect the pins that the relay should connect after it's powered, the pump starts pumping to the valve block. And the valve block is not letting air through.

Shouldn't the relay switch on by itself?

 

When I connect the pins that the relay should connect after it's powered, the pump starts pumping to the valve block. And the valve block is not letting air through.

I'm sure I have read airmatic threads (in the archives now) where guys have dismantled the valve block and cleaned it out. See if you can find it.

Shouldn't the relay switch on by itself?

I think that Airmatic should start when the ignition switch goes to position 2. When you remove the relay, do you get 12v dc at the relay socket pins which are for the pair of switched contacts. Careful here. The 12v is there all the time - even with the ignition key removed.

It must work the same way as on the W219 circuit above with the relay coil powered from unswitched 12v > fuse 9 (30A) > relay O switched contacts > air compressor motor > chassis earth. The relay operates when the ignition switch goes to position 2 and the coil is energised from N51.

Without a WIS W220 circuit here, my comments above are guesswork, however. :thumbsup:

 

if my 02 s 500 sags after 24 hrs on the left rear first should i suspect left rear air shock leaking or could it be from valve block...if it is the valve block can i re build it....??/

 

i have a 06 s500 and now everytime i drive and stop i get alots of air release front the front its like the transfer truck do when they stop what can dat be i never heard it before now it does it all the time its like a releif valve releasing air

 

Chiefdif, it is impossible to tell what the problem is without some troubleshooting. It is likely one or the other, but could also be a leak in the line to the rear strut. You can replace bad components, but likely you would not be able to rebuild them with what most of us have at home.

Roy mccree, this is just a guess - but your airmatic relay could have failed "on" and be overpressurizing your airmatic system. If so, that will also burn out the airmatic pump. Airmatic relays are expensive through the dealership, but can be had for far less through 3rd party suppliers - including forum sponsors and the parts sources listed in the W220 S-Class Encyclopedia sticky.

 

Resurrecting an old thread.

My newly acquired '05 S500 4Matic will raise the back end to max height about an hour or so after shutting the car off. According to this webpage that I found in the Encyclopedia (https://w220.ee/Airmatic#Valve_block_is_leaking_2), the problem is most likely the valve block. The following desrcibes my issue exactly.

Valve block is leaking

It is possible that valve block fails to close some valve in which case the pressure will be released back to strut rising the car too high. The vehicle is high only while the car is off, since as soon as vehicle is started the computer will try to adjust the level to the programmed level.

My question is, how much of an issue is this? The car corrects itself as soon as someone sits in a seat. I can't see where there is any undue stress being put on the system as the compressor is not killing itself trying to keep the car up. I will eventually replace the valve block but would prefer to move it to the back burner for a few months. Any thoughts or opinions are welcome.

 

The Airmatic system has a pressurized reservoir in the left front corner of the car. Your problem is probably caused by leaking O-rings in the valve block. Cleaning the valve block and replacing the O-rings would probably take care of the situation.

I have no idea whether over-pressuring the rear struts will damage the rolling diaphragms on the struts or not, but just in case, I would take care of the problem at my very earliest convenience.

 

I usually have pretty good google-fu but I have been looking for over an hour and cannot find a source for the airmatic valve block o rings. Plenty of links to ABC rebuild kits but nada for the airmatic. I wonder if the dealership carries them.

 

Duty cycle on the airmatic pump is going to go up some. If the valve block is leaking there is going to be a bit more than usual adjustment and refilling of the supply tank. I wouldnt think you would have many problems putting it off for awhile. A year may be another story, .

 

^ +1

 

And now the car is sinking at all 4 corners after turning it off. A couple of hours after parking it in the driveway, I went out and it had bottomed out. I started the car and got the red warning and the car would not come up. I pushed the dash buttons to no avail. I came back in the house to do some research and saw advice to check the fuse and pull it before working on the airmatic system. I went out to search for the fuse box and gave the system another try. No red warning this time and the car came up to standard ride height.

I turned the car off and waited. After 10 minutes it was down significantly. The neighbor's AC unit is hammering away loudly so it is difficult for me to hear what the pump is or is not doing.

 

12 hours later, the rear is still up but the front is somewhat down. I can still get 1 finger between the fender lip and the front tires. Does this sound like the valve block is going bad? A solenoid is sticking in the wrong position and one of the lines won't hold at the O ring?

BTW, I can't recall if I mentioned it before but the left front strut was replaced when I bought the car. Brand new from Arnott.