If the door locks don't work, for the time being I'd disconnect the line and plug the engine side fitting. You can fiddle with that later, shifting is more important.
However, a vac leak will make the tranny shift hard, not soft.
Disconnect the line on both ends and make sure you can blow through it 0-- if it is plugged, it can act as a one-way valve and hold high vac all the time.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!