Mercedes: 1983 lock problem, vacuum line, door locks

Question
I have a 1983 turbo diesel that is having a vacuum lock issue.. when I drive
around the back door locks unlock... the only way to lock them back when i park
is to lock the drivers door FIRST, then begin the annoying and time consuming
task of going around to each door to lock them.  Is there a vacuum line i can cut
to make them manual, or cheap way to fix the problem altogether?

Answer
It would be better to determine where there is a leak. The system can be check using a hand operated vacuum pump.
You many be experiencing a failure of the engine driven vacuum pump with gauges and hoses.
I would not try to cut the tubing as this could cause a failure of the whole vacuum systerm.
Let us know what you determine.
Rob