I bought a tap removal tool at Bascom's a couple of years ago. It works great and cost $12 at the time. It is sort of like a crow bar with an opening wide enough to go over a 7/16" spout between the 90 degree and the tree.

On the check valves that I have looked at while removing taps while under vacuum I could easily see where the ball was sucked back to close the hole. It has been warm here this season and I'm not seeing as much bacteria as I used to either.