Itinerant Air-Cooled

I have just started learning how to fix and maintain my 1973 Standard Beetle, so this question may be a little elementary to most of you... but I've just acquired a used SVDA distributor that looks like it's new. My question is: when I suck on the vacuum hose, the plate in the distributor turns counter clockwise. When I plug the line to keep the pressure at a constant level, the plate slowly turns clockwise back to its resting position. Does this mean that the diaphragm is bad in the vacuum canister, or do these things tend to return to the resting position unless a "constant sucking" is provided? In other words... is the canister good or bad?

Sounds like the vacuum can diaphragm is leaking slowly. Sorry.

The good thing is the general availability of SVDA vacuum cans. They are much easier to source than are the DVDA cans.

Satchmo