On my 1980 300D the door locks stoped working and i decided to test all the lines on the driver side floor and fron pass. side floor. One red and green line goes across to the fron passenger side floor and when i was testing those it wouldnt hold vac. All the others did except for the one going to the trunk element to i took it out and blocked it. It now holds it but very slowly leaks when checking it. Is that ok? After all of the test I started pumping with the mity-vac on the door lock check valve and then started to unlock and lock the doors it worked only twice then i lost vac. Do I need to leave the car running to fill the vac tank in the trunk? What does this mean? And when I lock and unlock the master Vac switch makes a leaking sound. Is that whats leaking? How do I check that?