tapping them with a tap and threading in a long machine screw with a few nuts that were bigger in between. Pulled them right out. Make sure you use a machine screw, not a self tapping screw and get enough threads into the hole first.
So basically you will have the screw in the hole and a few larger nuts acting as spacers between the screw head and the block. As you screw the screw in more it will begin to pull the check valve out. The nuts you use must be bigger than the diameter of the check valve and the screw will most likely need a few washers at the top of it. The machinest told me to use this trick and it worked like a champ. Just take your time and go slow.
