I put a 2nd gen vac pump in my truck for a hydroboost conversion...

Long story short, I don't need vacuum for anything, so I just put a black cap over the vacuum port on the pump. I pulled it off earlier today, and some oil started draining out. Is that normal?



EDIT: I accidentally a word in the title

 

Strictly a theory, but could it be since the vacuum pump can't pull anything at all, it is sucking oil in? I wouldn't think it would hurt much unless it starts getting past the seal, but I am not sure.

 

Haven't got a clue about that... next time I start it up I'll take off the cap and see what it does.

 

Oil would be normal.
The vacuum pump usually has a spring loaded check valve where you put the cap to keep oil from getting in the vacuum system when the engine isn't running.

 

Awesome, thanks. Is it perfectly fine to run it constantly with that cap over it?