[Vwdiesel] Crankcase ventilation / rotary vacuum pump

[Craig Osborn]

I recently purchased a rotary vacuum pump that was advertised as a bolt on
replacement for my old diaphragm type vacuum pump on my 1981 PU.
When I started to install the pump I noticed that it only had one hose
fitting whereas the old diaphragm pump had two hose fittings (one on the top
that went to the brake servo, and one on the side that went to the
crankcase).  
I took the car around the block after hooking up the vacuum hose to the top
fitting without attaching the crankcase hose to anything and I had the best
braking power that I have had in years.
I then called "Parts Place" to ask what to do about the crankcase
ventilation hose and they said that many of their customers were putting a
T-fitting on the top and attaching both hoses this way.  When I did this, my
braking power decreased markedly.
I then took my old diaphragm pump and spun the gear and noticed that it
pulled a vacuum in the top hose fitting but put positive pressure out of the
bottom fitting where the hose would attach that would go to the crankcase.
Given this discovery, it seems as though the recommended T fitting would not
be the proper thing to do.
Can anyone help me retrofit this pump properly on to my 1981?  Maybe someone
with a 1984 (when they started factory installing the rotary pumps) can
explain how their ventilation system is set up. 
 
Craig