Has anyone ever run into this? I couldn't build any vacuum so I started checking my lines. Changed a few tees but nothing changed. Finally got a few pairs of vice grips to isolate parts of my line and tracked a leak back to a single tap. Changed the tee, dropline and tap and still leaking. Using the clear CVs I was able to see air bubbles being pulled into the tap. So Im guessing there is a hollow spot in this tree and Im sucking air from inside the tree. 27" of vacuum with this line pinched off, little to no vacuum with it open.