Leaking Front Struts

[Detcomm]

DKo888, Thanks for the manual, that is so helpful. I also just bought a manual on a cd from ebay. I will install the software and see what goodies are on it.

Also, Like carlos said, i think he may be right "it is normal for the bellows to become undone as air is lost". This makes sense because only my passenger bellow came apart and that's the only one with leaking top seal.

BTW, do you guys think it's fairly easy to replace the bellow? Mine is a bit torn up -the rubber part is but the hard aluminum shell under the rubber seems fine. I wonder if i should change it and what tools i may need. They run $38 but seems that i would need a special tool for the top part.

[Detcomm]

dko888, Did you replace the strut yet? If so, was it difficult? I am thinking to buy the same if i cannot figure out my bellow issue. You only got one strut? What made you replace the strut? sorry if i missed it somewhere in a previous thread.

[carloslameiro]

Hello Detcomm, sounds like a difficult position, but don't worry, there is a leak somewhere, or your pump is not working properly. do you notice that one of the front sides raises, and not the other - or is it that none of the front sides raises?

Just this afternoon I filled my bellows, and yes, went ahead and prepared a video - just uploaded at:
YouTube - step e or 13 - filling bellows

Like yourself, I too had both my front wheels off the ground and both bellows "loose". According to the MB manual, the bellows should not be filled in the compressed position, and the bellow must manually be lowered to create the pressure (or negative pressure, in this case, not sure), for the bellow to stay. Now, given that all 4 car struts are in the same air system, I assume that BOTH frontal "loose" bellows must be manually lowered at the SAME time for the system to create the positive or negative pressure inside the bellows - working alone, this is impossible to do. So I decided to do as before, straighten the wheels, and lowered the car just enough to ensure that the bellows are "closed". i used my mobile camera and a light to ensure that the bellows are sitting properly before proceeding (you can also try to get your hand in there, with extreme caution, and feel the bellow properly closed). Next, I turned the car on, and waited a few minutes to then hit the raise vehicle button, when I heard the pump start, I lowered VERY very slowly each side until the bellow started to get pressure and raise the car to the "high" position, at that point, I could remove each hydraulic pump once the car was no longer supported by the jack. This is what I would do assuming the pump and realy are working okay, which is my case at present.

In your case, having changed the pump and relay, I think you need to ensure that the pump is actually working properly. This is what I would do. I would detach the tube from ONE of the frontal struts and brass valve, and keeping the other tube connected to the brass valve (keeping the car on the jacks, of course) with wheels ON the ground very slightly (ensuring both bellows are closed just enough). I would then turn the car on, and using your thumb, cover the loose tube - every few seconds, you should feel the pump pumping and creating pressure. If you don't feel pressure, just to make sure it is not the computer deciding not to pump air since the car is fairly high already (on the jacks), I would try pressing the lift-car button on the dash.

If you don't feel pressure on your thumb, either your pump is not working or there is a massive leak somewhere. Have you double checked all the tube connections to the new pump? You can also try changing the relay to the old one, just in case the new relay is not working.

If that side's tube has pressure building on under your thumb, I would try the other one - replace the loose tube, and undo the other tube. If both side have pressure this way, then your car may not rise if the both bellows are NOT properly closed (should be okay, having lowered the car just enough), or you are losing air via the upper metal seal/mastic - did you do bubble test?

Hope this helps - don't worry too much, it is fixable - just a matter of finding where the leak is.

Cheers

[carloslameiro]

By the way, I forgot to mention that after filling the bellows, I tested the car, and everything is working fine - no leaks! I think that for now, I will relax and enjoy the car and epoxy!

Also, as part of the leak test, after testing during 40km driving with potholes, speed bumps, sports level 2, I raised both sides of the car all the way on jacks, which usually created a lot of pressure in a leaking cap/valve - and nothing escaped through the epoxy. I also took the opportunity to check the bellows, and noticed that they did NOT come loose this time, and in fact, it was manually impossible to do so. This gives me a sense that the whole system I well sealed.

The bellows, i believe, are important, so Detcomm, you are correct in thinking about replacing damaged bellows. Be sure to tell us how you did it!

I will be back in a few months with another update.

Cheers

[Detcomm]

Carlos,

Here is an update as to what happened. The new compressor only turned on once for a short period of time. Since then, it has not turned on again. I replaced the relay wih old one and still the compressor would not turn on at all. I then removed the hose from the passenger top strut seal like you said and there was no pressure at all. This explains why that strut is sinking. I replaced the compressor with old one and it still would not turn on. Now i get 3 malfunctions on the dash.
1. airmatic, visit workshop
2. ESP, visit workshop
3. BAS, visit workshop

The brake pedal goes all the way down now and the esp button on the dash does not turn on when i push the button. I feel like i am totally screwed now.

I may need to reset the computer and not sure that's something i can do. I did disconnect the battery terminal and reconnected it but nothing happens.

I keep hearing about this star diagnosis, i may look into it. At this point, i'm sure the dealer will shaft me for couple of grand, especially if i tow the car there, they will sense desperation like sharks.

I never thought this will end up like this. So many people replaced heir compressors and did not have this problem. I guess it's not as simple as just replacing hardware.

Any advice from anyone is certainly appreciate it.

[carloslameiro]

Hello Detcomm, this is totally out of my league. It sounds like something was touched along the way. The ESP can ABS could at first simply be electronic, like you say requiring a reset, however, since your brake pedal lacks pressure, it sounds like that system has lost brake fluid - do you see any brake fluid leaks? - or the brake system pump (I assume the brake system has a pump), may not be maintaining the brake systems pressure, which again may be electronic, by not getting the right signal. I've just had my benz for 2 months, so I haven't had time to play with the mechanics, or read up on the sytems, so I myself can't be of much help. Good luck, and be sure to document your thoughts and investigation, since the actual trouble shooting can help us all. If the car was working well before you got in there, I assume that the problem must be relatively minor - but electronics is somewhat complex and may require more advanced equipment, like the STAR system you mention.

Take it slow and steady, and let us know how it goes.

Cheers

[Detcomm]

Carlos and others

With the help from other threads i fixed the problem.

here's how the malfunctions happened.

when the front end was jacked up with wheels off the ground, i was turning the wheels back and forth with the engine turned off to take a look at the struts and when i started the car i was getting these esp and bas/abs malfunctions.

other people had the same problem and they suggested i do the following:

turn car on and turn the wheel all the way in both directions, turn offcar and restart. this took care of the problem. I know there was no problem with this before. The computer must have gotten confused when i turned the wheels earlier with the engine turned off.

stupid design if you ask me but i am indeed thankful its fixed. Just keep this in mind if you ever run into similar issues.

[dko888]

Detcomm,
My front passenger air strut has air and fluid leakage, so it's not repairable. The replacement strut has not arrived yet, will let you know how it goes with the replacement.

[OliverK]

fwiw, does anybody know the torque figures for the three mounting bolts on the strut top mount?

[dko888]

Front Air Strut Torgue Figures

Nuts (3) top - 20 Nm
Bolts (2) bottom - 20 Nm
Air Pressure line to Strut - 5 Nm