nath_h

Yes, you are correct about the location on mine. The CL is just the coupe S class. They used to call it CL, before they switched to S coupe in 2014. Everything is the same except obviously some body parts, and some interior parts.

msiumng

Just an update, I have taken the pump out from the trunk, check all the connections there, doesn't seems to be any leak from there, I did it in my garage late at night when it was very quiet and I have someone in the car adjusting the seats, the pump works fine and no hissing when holding air from there. So probably next step is to take out the side bladder since most of you guys had experience a leak there. But like BOTUS saids too really none of those features are important or I have desire to use it at all too, I guess I will just need a very chill weekend to motivate me to take the next step.

nath_h

Update for me...No hissing in the trunk area, but after shutting off the car, I hear a leak somewhere in the backrest. It is not subtle, either. I'm assuming this is not a designed pressure relief post shutting off (someone please correct me if I'm wrong). I'll take off the back panel later this week and hopefully can identify what is leaking. I'm surprised, because I thought I had replaced everything that could go wrong in the backrest. I also sat in the passenger seat and turned on the massage--way more pressure as the unit cycles through. So, the driver side is just not able to build enough pressure, and shuts down. With that said, it has never worked correctly and cuts off after one cycle, so I think I may have more than one problem.

BOTUS

there is a software update for the pump - no idea what i does, had mine done in 2019 when we were playing

Arrie

So, you are getting there. Don't be surprised if it is that pressure safety valve on the tank. Could be cracked air tube connection to the tank too. But it is something simple when you find it.

Tank was about $350 when I replaced mine when the valve alone was not available from MB. It is easily changeable valve if you could buy one. I bet in Europe it is available.

If you remove the air tank do not try removing it alone. There is a screw on top left corner you cannot get to. You need to remove the whole bracket with pump and tank. It comes out easily, at least in the W221 it does. Four screws if I remember correctly.