Loose vacuum output fitting on dual function pump

See video link. My brakes are always marginal. I put a gauge on it and have like 12. I wiggle it I can get it to 16ish. what is normal vacuum? Any idea on how I can fix this as it looks fitted from inside to out, does not tighten thread wise.
http://youtu.be/iO4_xk1OIqc

I've never had the tandem pump apart on our Passat, so I don't know the configuration, but it looks like there's a seal missing in there.

Mine was loose when I did my cam/valves, etc. I was able to "stake" it into place using I believe a socket and of course a BIG hammer.. jk. Tightened up very nicely. Of course the pump was off the car.

It looks as though yours it much worse off than mine was, btw

Depending on the date of manufacture, it might be a recall item. A quick search on the web will give you the date. You can check the marking by using a mirror and a flashlight on the firewall side of the pump. If it is a non recall, then the fitting has come loose. Mine did. After sealing mine with silicone, it lasted about a year and then started leaking diesel down the back of the engine block and running poorly at WOT. Had to replace and a new one was about $230.00