On my 300CE the drivers seat stays in the locked position all the time, vacuum or not. It will not release and is a pain to access the left rear seat if not impossible! Is the catch attached to the vacuum pot spring loaded to pull off when the vacuum disappears? If so, where is the spring located on the seat? This is what I suspect but without removing the seat, unable to see.

TIA
Tobias MB
4 MBs