charmedes

Hi! My 99mod S320 petrol Mercedes lays low on the front right side after few hours without driving. The rear right side also lowers a little bit, but not as much as the front right side. The top strut seal is fine. I have replaced the sealing a few years ago, and tested them with soapy water today. Whats most likely the cause of this problem? Hose leakage? Leaking valve somewhere? Or just a broken strut? I left the car sitting for some months before the summer, and when i came back, the whole car was laying low.

wallyp

Possible causes:
A leak in the fabric and rubber rolling diaphragm (the primary support) inside the strut. Replacement of the strut is the most practical approach. It is also the most expensive, so you want to eliminate any other cause first.
A leak in the air line from the valve block to the strut.
A leak in the valve that feeds that strut inside the valve block. Possible, but less likely.

martinzx

It could also be a level sensor.

Cheers Martin

wallyp

I doubt that a level sensor would give this set of symptoms - if the sensor is faulty or improperly linked, the improper level would be held constantly. The level would not drop when parked, then rise when the engine was started.

martinzx

Maybe not, but I have the similar issues on the front of my car and after replacing the strut it is just the same.( Mine is constantly just a little lower). Mine is not leaking at the top either, before or after, I am still investigating to find the problem.

Cheers Martin

wallyp

Totally different symptoms - his is at proper level when driven, leaks down when parked. Yours is always low.

Yours can be a faulty sensor, but a little more likely to be bent or maladjusted linkage or attachment of the sensor to the vehicle. It can also be a software problem - you can set the ride height of each corner in the software. you will need to use DAS to fix a software problem.

martinzx

Fair enough...
Thanks for the advice, it is not the suspension or linkage, it could be the attachment or the sensor. It is not the software as it was set last week. I will find out more tomorrow.
I appreciate your experience.

Many thanks
Martin

wallyp

The "linkage" that I was referring to is the linkage from the sensor to the suspension - it is not unusual for the linkage to get bent or maladjusted, causing the sensor to send the wrong voltage, resulting in ride height being incorrect.
It also is not unusual for the mounting of the sensor to be off, which will also affect the ride height. These two are the most common causes for the problem that you report.

"It is not the software as it was set last week."

Does this mean that someone with DAS and the special angle sensor set the corner ride heights? If so, why is one corner incorrect? Using DAS and the sensor (although it is possible but difficult to do the setting without the angle sensor) can set the individual standard ride heights for the car as it sits.

martinzx

Thanks for the clarification. I am not experienced with the airmatic, but I am learning quickly.
It was in the garage last week for a fair amount of other work, which included changing the front strut. I brought the car back near the close of business on the same day, they then set the height using the Mercedes software, and to be fair it was also quite busy... I had previously arranged to bring it back tomorrow to check over other things. I will get them to look at the ride height again and hopefully resolve the issues. The garage I am using is the best indie in the city so I quite confident they will be able to resolve it.

Cheers Martin

wallyp

This might simplify your life a bit...

https://w220.ee/Airmatic

martinzx

It is quite a comprehensive resource, Thanks.

My issue is now repaired many thanks. FYI it was the linkage that mounts the sensor that was adjusted and reset several times until it was optimum

Cheers Martin.