Originally Posted by billrei

I hooked my Mityvac to both the lines going to the tank and to the ones going to the canister and I could not generate any vacuum in either direction. I'm not sure how the system built up that much pressure. I'm not a fan of quick fixes but I'm glad I drilled the vent holes in the cap. I filled the tank up coming home from work and when I got home there was no vacuum present at all. That little mechanical pump must be working much easier now.

I'm sure the two little .050" vent holes I drilled won't add to global warming. Gosh with all the talk about R12 on this list I'm surprised we even still have an ozone layer...