rik881

I tried inflating the car like that but it is not so easy, i should have to make something to keep the cable connected and i don't know which is ground and which is positive.

tusabes

Yes definitely set the car on the ground before trying airmati

tusabes

Take all the jack stands out

Let the wheels and car sit in the ground then see if it lifts

rik881

Compressor came on for like 60 seconds. Car did not lift and i think i heard some hissing at the rear left wheel but it could be the fuel pump. I started the car and the car too low message was back.

rik881

Update: compressor does come back on but it is not lifting the car.

tusabes

Spray all the struts and air lines with soap water , and look for bubbles to see where the air is escaping

rik881

That's what i'm trying to do but i just don't see how. The compressor only comes on when the car is all the way down. So i can't get the wheel of to spray everything there. I got the compressor out and i did not see any leaks. I did spray the top of the front shocks i did not see any bubbles there. One has hairline crack other doesn't.

I jacked the car up al tiny little bit and i have let the compressor come on for almost 20 times but it does not rise at all.

rik881

Also why does the compressor always stop after less then a minute? It will come on later though it seems it should keep running.

Thanks for helping me out you guys have been a great help so far!

tusabes

It should be able to raise the car in just a few seconds , it should never take longer than a minute

wallyp

If you have the proper types of jacks, lift under the rear differential and lower the rear jackstands slightly, then lower the front slightly, repeating until you get the car just under the normal ride height.

rik881

Jacking the car is not so much a problem i have 2 nice low jacks and i jack the car just a little bit. I disconnected the filter to compressor hose. When i top of the hose going to the compressor i feel almost nothing. It sucks air i think but it is so weak i almost can't feel it. That can't be correct i guess?

rik881

I disconnected the hoses to the front air shocks while compressor was running and there was no air coming. Left side did lift a little though. I then filled the shocks with air from a working compressor and the car lifts. Left side stays up, it drops a little and then stops at a good riding height. Right side though drops all the way down. I'm going to try to get the rear up same way. So far i think i'll need a new compressor and probably a repair kit for right front shock.

tusabes

There is a piston seal kit for the compressor

That's probably all it needs

See here
https://mbworld.org/forums/s-class-w...-continue.html

wallyp

There is no repair kit for the struts that is practical for the average home mechanic. Replacing with rebuilt struts appears to be the most practical repair, with Arnott being the recommended vendor.


The piston ring kit is about $25, not difficult to install.

rik881

Compressor repair kit seems very nice, too bad it takes so long to arrive. Maybe i'll go for a good used one.
I tried inflating the right rear shock as well but it doesn't work. . Air escapes somewhere underneath, i can not find where. I tried the hose but that seems to be ok. There is so little space under the car that i am having a very hard time localising the leak.

rik881

i'm confused. There's 4 shocks. I filled all with air manually.
1. Left front stays up. No air coming out anywhere.
2. Right front comes right up when i fill it but doesn't stay up air escapes from the top. If the compressor would be connected it would not leak because of the valve i guess. Since it doesn't leak on the lower part of the shock i gues the airbag inside should be ok.
3 Right rear leaks so much it almost doesn't rise, air escapes somewhere on the bottom part of the shock. I don't think air escapes from the hoses. Shock seems to be broken. I guess the airbag inside broke when jacking and lowering the car with no air pressure since the compressor is too weak. Rear shock can not be repaired it seems so i might buy a used working replacement.
4 Left rear rises when i fill it but valve doesn't close just like right front

my questions are: which shocks do i have to replace? what's wrong with the valves? Why does one shock keep air and why do the other shocks throw all air out?

tusabes

The right front probably just needs a strut top repair kit

Get two rear arnott struts

rik881

Arnott might be a very good replacement but they a bit out of budget. I have found 2 new rear shocks for 600 on Ebay. That's almost 1/2 the price.
Front tool cost 120 usd and the repair kit about the same. Ebay has new front shocks for 340. I still need the compressor repair kit and intl shipping.

What i've found so far is that second hand struts are pretty expensive sometimes even more expensive then new ones.

Going to give it some thinking, there are 2 good solutions, new shocks/compressor or the spring conversion which most say to be not very comfy.
Thanks a lot for helping me out, work isn't done yet but now at least i know for sure what i'm looking at. A1

rik881

I have decided. I'm going to buy new shocks. Cheapest front strut i've found is 288$ Rear 600$ for both. Going to order them next week should be three weeks for them to arrive. In the mean time i'm going to bench test the compressor and if necessary i'll buy the seal or a good used one.

So now i want to take a closer look at the dash buttons. I don't think my Sam is fried. I think the buttons must have disconnected or may be the are broken but Sam has to be fine. So while i was looking for a used one i saw they all have different button setup. Some have esp on the left others the rear curtain button. Mine has parking sensors on the left. Some have 6 buttons and hazard others 7 or 8 like me. Are these interchangeable? Because i can't seem to find the same one.

wallyp

It is entirely possible that the compressor is good - a new, perfect compressor won't keep up with a blown strut.


If the compressor runs relatively quietly, with no odd noises or smells but doesn't pump enough air, the $25 piston seal would be my first choice.


I'm not trying to talk you into or out of anything, but I do want to say that it appears that you have two known problems - one blown rear strut and one leaking front strut.


Replacement is the only answer for the rear strut. I think that Arnott is about $450 after return of the core, but they may not ship overseas - it is helpful to have your location on your posts. If you could find a good used strut locally, that would probably be cheapest. There is no need to replace both if only one has failed.


If you opt to repair the leaking front top seal, you can buy the tool, use it and then sell it, recovering most of the cost. That would make the repair cost perhaps $130-150.

rik881

I have bought a brand new shock for 274 on Ebay. Only 3 left. Rear i have not bought yet. I'm going to bencht test the compressor now.

rik881

I didn't get to remove the compressor it doesn't give any pressure anyway. I removed front hose to strut both sides and there is absolutely no air coming when compressor is working. When it stops though it seems as if there comes a tiny bit of air. Strange to say the least.

I tried inflating rear struts and i think, no, i know i made the leak worse
i heard the air coming slowly and then woosh a whole lot of air. The other one though doesn't stay up nor does it leak from underneath. The valve on top of the strut throws out all air. Does that mean this strut is also to be replaced? I read that it is a common fault on the front ones.

The front stays up more or less. I think it should be a little higher then it is now but it was good enough for a testdrive. Everything acts normal no other warnings then the car too low. All i have to do now is wait for the struts to arrive and the compressor thingy.

wallyp

You have a compressor that when required feeds air to a pressure reservoir. The air reservoir feeds pressure to a valve block. The valve block, with individual valves controlled by the computer, feeds air to each of the struts.


Taking the air lines loose at the valve block doesn't really show whether the compressor is working.


The rear strut had already failed when you applied air pressure. If it leaks at all, it has failed. It has to be replaced.

rik881

Thanks for the explanation! Just one thought though, the car was way down when i disconnected the strut and the compresor was working. Shouldn't there be pressure?

I'm starting to understand the procedure. My friend has a Audi A8 with the same type of air suspension which has also collapsed. The Audi even has the same compressor, just as a lot of other cars which have air suspension and they all seem to suffer same problems.

tusabes

All air suspensions fail at some point they don't last forever like steel springs