[samosali]

If the left front strut is too high, that will push the right rear down. For the moment, stop worrying about the right rear. Get the left front fixed. Your could try replacing the residual air valve if you can get one that works on the cheap strut.

cool, so we have narrowed my aim considerably. I do not know how to change only residual air valve. Isn't it inside the strut? Or is that thing which is at the top of the strut right which couples with air line connector? please explain ... anybody?

 

[samosali]

Actually it's very easy to change out the air fittings, and you'll just need a plier to remove the old ones and then slip new ones on. I've never needed to cut anything off. Just make sure the air line tip is not crooked. The fittings on your amazon link look fine.

i guess you agree with wallyp, so you did not add anything regarding main topic. Thanks for explaining about the connectors. Will manage it.

 

[event3horizon]

i guess you agree with wallyp, so you did not add anything regarding main topic. Thanks for explaining about the connectors. Will manage it.

I agree with wally to focus on the front left strut for now and yes, that valve (if it IS the problem!) can easily be screwed off on the top and replaced, if you can find replacement.

 

[samosali]

I have ordered 2x residual valves from amazon

Amazon.de

Please one thing more. I have learned how to pump air in and how to release it in SDS. I use adaptation values or something like that. Not initial startup. Maybe it is not important. HOWEVER, after setting the desired height of all 4 corners there is another step which demands some measurements of 4 angles (angle of rear shafts and front lower control arms), for those who know what i am speaking about it is clear i guess. So what about this last step. I have some difficulties to understand how exactly to measure and what to measure and is this important at all.
Please somebody enlighten me, many thanks!!

So far I will not touch the valve block. I can always buy one and replace it but i hate to touch things which maybe work.

P.S.: i guess i have to put a jack stand below the left front end of the car before replacing the residual valve. the strut should be under the pressure according to my logic.

 

[cowboyt]

Personally, I wouldn't bother with measuring those angles. Just have the car on a flat, level surface, and then adjust the height of the car at each of the four wheels until it looks even. Again, about 2.5 to 3 cm should do it.

 

[event3horizon]

I have ordered 2x residual valves from amazon

Amazon.de

Please one thing more. I have learned how to pump air in and how to release it in SDS. I use adaptation values or something like that. Not initial startup. Maybe it is not important. HOWEVER, after setting the desired height of all 4 corners there is another step which demands some measurements of 4 angles (angle of rear shafts and front lower control arms), for those who know what i am speaking about it is clear i guess. So what about this last step. I have some difficulties to understand how exactly to measure and what to measure and is this important at all.
Please somebody enlighten me, many thanks!!

So far I will not touch the valve block. I can always buy one and replace it but i hate to touch things which maybe work.

P.S.: i guess i have to put a jack stand below the left front end of the car before replacing the residual valve. the strut should be under the pressure according to my logic.

These are the "Romess angles" you’re referring to and are the inclination angles measured by a Romess inclinometer. These angles are important for ensuring the vehicle’s air suspension is properly leveled and aligned to factory specifications. Basically, it's a precise measurement of the suspension geometry.

In this context, the Romess angles represent the inclination (or tilt) of specific suspension components—typically the lower control arms—at each corner of the vehicle (front left, front right, rear left, rear right).

These angles are measured in degrees and are entered into the SDS/Xentry during the calibration process to set the correct ride height. The inclinometer is placed on designated points (often small mounds or flat surfaces on the control arms) to determine the angle relative to a level surface. The goal is to ensure the vehicle sits evenly and matches the factory-designed stance, which affects handling, comfort, and tire wear.

Each Mercedes-Benz model has specific target inclination angle ranges, which can vary depending on the chassis (e.g., W211, W220, W166). These ranges are provided in the SDS software and are typically broad enough to account for slight variations in measurement or vehicle condition.

People usually just put it in some known pre set values for the w220 to avoid dealing with the actual inclination measurements when calibrating.

 

[samosali]

Ok, so i have two options: put some values found on internet, or measure the whole thing. From internet i can see what is negative and what is positive angle, so i think i have chances to put in real values. rear axes have negative values, so the opposite inclination is positive, which is at front end. I will study internet how to put real values in. i must also ensure that (i) car will be leveled in respect with floor and that (ii) all corners will be leveled. i will not measure angles, i will rather measure distances from floor and use some geometry, does it sound reasonable?

Can you please confirm this: SDS did not allow me to store these settings (which i found on internet), because they were "out of range" or something like that. I guess that it is so because of too big differences in levels of 4 corners, not because of these values. So now i have one error in airmatic system which is that calibration procedure is not completed. All will be good after i fix the levels. Does it sound right?

 

[event3horizon]

Ok, so i have two options: put some values found on internet, or measure the whole thing. From internet i can see what is negative and what is positive angle, so i think i have chances to put in real values. rear axes have negative values, so the opposite inclination is positive, which is at front end. I will study internet how to put real values in. i must also ensure that (i) car will be leveled in respect with floor and that (ii) all corners will be leveled. i will not measure angles, i will rather measure distances from floor and use some geometry, does it sound reasonable?

Can you please confirm this: SDS did not allow me to store these settings (which i found on internet), because they were "out of range" or something like that. I guess that it is so because of too big differences in levels of 4 corners, not because of these values. So now i have one error in airmatic system which is that calibration procedure is not completed. All will be good after i fix the levels. Does it sound right?

Well I'd think it would hard to do any kind of measurements if the car is not on a 4 post lift sitting level, but if you have a method then by all means go ahead. When I did my airmatic calibration, I didn't do any measurements. I found values for w220 online which worked fine and the airmatic computer accepted them. It will not accept out of range values as you have seen and if the level sensors are not within voltage range it will also fail.

 

[samosali]

more i think more i am sure that i will also not make measurements. Because measurement error can easily be larger than measured parameter. I found this on this forum;

so for Euro 4Matic front is -0.8 degrees and rear is -1.1 deg. So it will be.
I am waiting on spare residual valve to fix non responsive front left strut.

I am doing fluids, exam of whole car, valve cover gaskets, front duovalve, etc. I use (used) button for lifting the car many times recently. Today i have noticed that the car does not go down when the button is depressed again (red light turns off). Is this related to Airmatic error on my dash and not successfully completed level calibration? Or is it another episode? I guess the car will not lower on three corners only, front left residual valve is evidently stuck closed or almost closed. If so, I can be calm and wait for parts. Does it sound right what i wrote?

 

[event3horizon]

Yes, airmatic doesn't do much of anything when there is a hard fault stored.

 

[samosali]

excellent. and logical. Thanks so much.

 

[samosali]

something is not clear to me. So why do videos and WIS say to depressurize the system before strut replacement. There should not be any pressure in lines from valve block to struts (assuming the valve block is not faulty). (UPDATE: there should be pressure in lines). I also do not understand why the whole car should be in air when replacing one strut for instance. All other three struts have residual valve which prevents the corresponding corners to be lowered too much.

I am asking this to check if it is right that nothing happened when i have removed air line connector from left front strut, so there was no pressure leak after the removal. due to (maybe) bad residual valve in this particular strut there was no pressure from the strut also.

So where is my problem in understanding the system? And secondly, is it possible in theory that residual valve is bad on the RearRight strut also? if it hinders the air to come in then this corner will not be raised enough (fast enough).

Maybe i made a mistake to buy residual pressure valve. I did not think about removing the black "plastics" on the top of the strut in order to get valve out. So I will need to put some epoxy back after the replacement?

In addition, here is one thread which is almost identical to my problem and it turned out the culprit were both rear chinese struts and the car was too high at rear end. Using Arnott fixed the problem.

https://www.benzworld.org/threads/cannot-low-the-front-when-disconnecting-residual-pressure-valves.3033496/

so i think i only have small chances that replacing the residual pressure valve will work. Maybe I should just buy one Arnott for FrontLeft side and that is it? I will definitely fell better with Arnott instead of current no name crap.

Still, it is not clear to me if removing the air line from the top of the strut should release air from the strut if pressure in strut is let's say 10bar or more which is most probably in my case. The point is that i do not know how exactly does residual pressure valve work. Namely, it is hard to believe that the air can come in (raising) but it cannot come out (lowering which does not work in my case).

This picture shows that there must be a pressure from both sides in order to get air flow in any direction. So if i am able to pump air in (build pressure in strut up), then it also should work in opposite way ... or maybe not. I give up.

US20110278775A1 - Residual pressure holding valve and suspension strut - Google Patents

A residual pressure holding valve ( 1 ) for a hydropneumatic suspension strut ( 2 ) of a motor vehicle has a valve housing ( 3 ) with an air inlet ( 4 ) and an air outlet ( 5 ). A valve body ( 6 ) is arranged displaceably in the valve housing ( 3 ) and a valve element ( 7 ) is arranged...

patents.google.com

 

[wallyp]

If there is pressure in the strut, it is pretty much impossible to get it out of the car.

You are still worrying about the right rear. If the left front is high, it will push the right rear down.

 

[samosali]

yes, that's what i thought, too.
i am worrying because it happens so rarely that our expectations come true. But yes, physics tells us so, it is a lever effect. less on side to side and more from rear to front due to bigger distance. i am waiting for the residual pressure valve. Do i have to free the valve of the black plastic around it or is it ok to just unscrew it ... maybe you know?

 

[samosali]

So, today i received the residual pressure valve. I lifted front end of car and put it on stands. then i replaced the left front residual pressure valve. Then i tried to put some air in the strut. it was not more than 8.5 bar. i did the same for FrontRight strut which is MB original one, replaced once in the past. I was again not able to release air from LeftFront strut. Only first try works, then it stops.

The LeftFront strut started to leak and there was ca 10 ml (or more) of oil on floor. the ribbed dust protection for strut was separated from the bottom part of the strut. I knew it is dead but i played with it in Xentry. Somehow I did a calibration so all struts are approximately at same height. I removed the linkage from level sensor and tested the sensor in Xentry. It works. Even if strut does not release air, there is CLICK sound from valve block. And even if releasing of air does not work for this strut like in other three struts, it evidently works somehow .. with a delay or something like that, do not ask me. I can work with other 3 struts whatever i want but the LeftFront one behaves in a special way.

test drive: thumping noise from LeftFront wheel. I am going to buy Arnott for ca 650 eur here. I would rather not touch the valve block because i like saying do not fix it if ain't broken.

testing valve block to strut connection passed for all 4 wheels. I guess the procedure pumps pressure and releases it. All 4 corner levels are now within 10 mm.

the most important thing: did i make a mistake to pump air into strut on a car with wheels in air? If yes, why did the right one survived without consequences? Or is it just because it is cheap chinese strut which was on its last leg and i only helped it to die?

I have found this one on ebay, what do you think, is it possible that original MB strut is 500 eur only?

Bitte entschuldigen Sie die Störung...

update: and one more thing: when i raise and lower the car with button in the cabin then both directions work flawlessly. this is just not logical to me, so why is then lowering in Xentry so difficult for FrontLeft strut?

 

[samosali]

i have studied WIS however i want to be 100%sure how to install the new strut. Can someone just write short instructions what to care about.
-Can i raise only the affected corner and put jack stand under it?
-is it ok to just disconnect air line at the top?
-what to do after the new strut is mounted? To fill some pressure in it (Xentry) like 5 bar and then i can lower the car onto the ground?
thanks.

 

[event3horizon]

i have studied WIS however i want to be 100%sure how to install the new strut. Can someone just write short instructions what to care about.
-Can i raise only the affected corner and put jack stand under it?
-is it ok to just disconnect air line at the top?
-what to do after the new strut is mounted? To fill some pressure in it (Xentry) like 5 bar and then i can lower the car onto the ground?
thanks.

I can tell you what I've personally done (with good results). Can't tell you what is BOOK procedure. It probably involves you standing on your head at some point. Anyway:

1) Yes, without issue.
2) Yes, unscrew slowly.
3) I lower that side slowly, until it is a bit under proper level, then wait for airmatic to raise it up to proper level. I do not lower the jack all the way abruptly. You can probably use xentry to do this manually. I never used my scantool for this since it doesn't continuously raise the strut, I'd literally have to keep pressing 'raise' on it like a 100 times, but that's because I'm using third party scantool.

 

[samosali]

I can tell you what I've personally done (with good results). Can't tell you what is BOOK procedure. It probably involves you standing on your head at some point. Anyway:

1) Yes, without issue.
2) Yes, unscrew slowly.
3) I lower that side slowly, until it is a bit under proper level, then wait for airmatic to raise it up to proper level. I do not lower the jack all the way abruptly. You can probably use xentry to do this manually. I never used my scantool for this since it doesn't continuously raise the strut, I'd literally have to keep pressing 'raise' on it like a 100 times, but that's because I'm using third party scantool.

cool, thanks. i just had to check. i can tell you that Xentry works also with method "press-it-100times-to-pump". no continuous way. i guess it is due to safety for struts not to explode or car not to fall down too fast.

 

[wallyp]

After you complete the strut installation, just remove the jack stand and lower that corner until it is slightly lower than the desired ride height. Start the engine. The Airmatic system will add air until that corner is at the proper ride height.

 

[samosali]

After you complete the strut installation, just remove the jack stand and lower that corner until it is slightly lower than the desired ride height. Start the engine. The Airmatic system will add air until that corner is at the proper ride height.

that's what i need, thank you Sir.