I picked up a 2015 s550 4matic with 20k miles last summer. I got the AMR tune and love driving it. I was hit 2 months ago in a minor collision and it’s been at an indy body shop for the last month. They sent it to Mercedes to calibrate the new headlight and Mercedes told them my front driver’s side strut is leaking.

I recently hit a bad pothole going 80+ on the interstate and destroyed the sidewall of the runflat, so maybe it damaged the strut as well. But maybe the fact that the only tow shop open at nearly 11pm just happened to have a used tire that was a slightly different size than the oem tires has caused them to see a different gap between fender and tire on that side and assume a leak. Either way, I’m not letting them replace it, I will either do it myself or take it to an indy shop. The car was not obviously unlevel when I dropped it off. I have a new set of wheels and tires ready to install as soon as the car comes home. Once the off-sized tire is replaced, how do I test the strut at home? Is it as simple as parking it, measuring ground to fender and then re-measuring after some time has passed?

If it does need to be changed, will I need a diagnostic tool to bleed the air? I have only been able to find a video on changing the rear struts and it did not look like something I want to try, partly because it said I needed to have a diagnostic tool to bleed and to repressurize the system if I remember right. Is the front strut a quick “unbolt and swap” or will I have to buy equipment to bleed and refill the air? Can anyone link a video to show front-strut replacement on the w222 (assuming they are all the same as the 2015)?

The install question is regarding the Meisterschaft GTHaus exhaust with remote controlled valves. I’ll take delivery on that next week and was curious if anyone here had done the electrical connections. Does this require drilling through the floor into the cabin or is there electrical available underneath the car and if so, which wires are people tying into?

Sorry for the length of the post and thanks for any help you can provide.

 

Bilstein has an installation tutorial series that walks you through the full process of removing and installing the front and rear air struts on the W222.


Typically, the earliest signs that an air strut is failing is before a cold start when you're greeted by a vehicle that has one corner significantly lower than the rest. The car will level once started, but if the strut is consistently low or collapsed after setting for several hours, then you should replace the strut. Besides affecting handling, driving with a failed/failing strut forces the Airmatic compressor to run longer and more often, which diminishes its life.

BTW, I'm an advocate of replacing Airmatic struts in pairs if possible. Due to cost, people tend to replace them individually, but experience has taught me that the handling dynamics with a new strut on one side and an old strut on the other is quite noticeable. Replacing the front set and rear set at different intervals is fine, but IMHO, I would not replace just one strut on an axle. If you're an enthusiastic driver like me, you'll notice it.

 

Don't the airmatic units have a hydraulic dampening unit (aka shock absorber) inside? If so, that would be another reason to replace in pairs since you'd have a brand new dampener on one side and a worn one on the other side.

 

I had a bad dampener in the strut of my front drivers side strut on my MY2015 S550 4M. Strut did not leak but would make a clunking sound when coming off a speed hump. Very easy to swap with no special tools needed. I have a set of quick jacks that I use as I don't have the space for a full lift but I would think you would want to raise the entire car to do the job as you want to take all the pressure off the suspension. Once I raised my car I slowly unscrewed the air fitting on the top of the strut and the remaining air escaped. Swapped out the strut per the video posted above and dropped the car to its normal height but still resting on the lift. Started up the car and pushed the raise button. After 10 seconds or so the car raised up and leveled itself out. Dropped it off the lift and took it for a test drive. All works fine now. Picked up a reman unit from a shop out of Florida for around 400 bucks with core exchange. Very easy to do if you have access to a lift. I do recommend an alignment once the work is done as you are messing with the suspension a bit. I do not notice any difference between the two sides though with one being 5 years old and the other new. While it is up in the air you can also install the new exhaust. Not sure on the wiring though.

 

Thanks for the replies and the videos. If it’s easy to do the driver’s side (sounds like it will be), then I’ll do the passenger side as well. are all remanufactured struts equal, or is someone doing a better job rebuilding these that will make it less likely to fail in the future?

 

I only found 1 US based rebuilder, RMT in FL. New was around 1200 each and rebuilt was 400 or so. I do not think these things fail very often so I was not worried about a rebuilt unit. Seems silly to replace both of them but do what you want, they are easy to swap.

 

So you didn’t use the diagnostic tool shown in the video to bleed or repressurize the system?

 

No, there are leveling sensors on each front A arm that tell the cars computer where each strut is and the computer sends air to any shock that is too low or too high. I did not use any diagnostic tool, there is no bleeding because it is air. I did measure from the floor to the top of each front fender arch to see what the measurement was and it did not change even a MM when I was done.

 

That’s good news. My hold up was bleeding via a diagnoatic tool that they show in both front and back installs.