Multicontour Seats




So, my multicontour seats stopper working. iCarsoft reads that the pump is overheating and shut down. Reason is leak in the system.
Took the trunk lining off to get to the pump and after pump cools down it runs again but air leaks out thru the pressure safety valve on the reservoir.
The obvious fix is to get a new reservoir as the safety valve cannot be purchased separately but then I thought that what if the pump does not shut off at set pressure like if the pressure switch is bad? With this thinking I measured the pressure the pump puts out and I get up to 30 psi.
So, does anybody know what the pressure should be as 30 psi sounds a bit high?




So, my multicontour seats stopper working. iCarsoft reads that the pump is overheating and shut down. Reason is leak in the system.
Took the trunk lining off to get to the pump and after pump cools down it runs again but air leaks out thru the pressure safety valve on the reservoir.
The obvious fix is to get a new reservoir as the safety valve cannot be purchased separately but then I thought that what if the pump does not shut off at set pressure like if the pressure switch is bad? With this thinking I measured the pressure the pump puts out and I get up to 30 psi.
So, does anybody know what the pressure should be as 30 psi sounds a bit high?




As both seats went out at the same time it kind of had to be the air supply issue, i.e. the pump or the reservoir. It was the safety valve of the reservoir that failed and, of course, it cannot be purchased separately so I had to get the whole reservoir for $247+fax.
Again, an easy job after you figure out how to remove the trunk lining to get to it. Hardest part of the job is to get in and out of the trunk.




thanks for the very good documents. I actually found your post in another thread with the trunk paneling removal after some search so I was able to get to the pump/reservoir.
Then I removed the reservoir and pump without taking the holder for those out. The "ear" for the reservoir on the left top corner broke off when I tried to figure how to get it out after removing the right top screw but this was no biggie as I had to get a new reservoir for the faulty pressure safety valve anyway, but it showed me that the holder for the pump and reservoir has to come out to be able to fasten the top left screw.
I wonder if the safety valve is available in Germany for their local customers there as the valve comes off of the reservoir with squeezing two tabs and pulling it out? It certainly is made the way that it is easy to change if you have the part.
I was able to install the whole assembly without taking the rear self support out but it was tight to get it in. If I even have to do this again I will take that support out first.
Thanks again!
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Are you sure it is only the driver seat that goes out? Mine was both so it had to do with the pump unit.
What mine did when I tried to change any setting it would not take the new value when I selected it. It just jumped right back to the value it had. It first seemed to be just the driver seat but after going thru the settings on the passenger seat it was the same.




https://mbworld.org/forums/s-class-w...ml#post8152190
BTW - I continue to have Dynamic seat issues where they 'return to zero', but a stop and restart of the car usually resolves them.
They are not related to leaks (I have checked!) so likely software/hardware.




https://mbworld.org/forums/s-class-w...ml#post8152190
BTW - I continue to have Dynamic seat issues where they 'return to zero', but a stop and restart of the car usually resolves them.
They are not related to leaks (I have checked!) so likely software/hardware.
And I could not hear the leak from the safety valve until I removed the lining behind the rear seat in the trunk.


