So did this about a year ago, got a newer unit that I cleaned up really well and am going to swap in.

WTF?! How much coolant is supposed to come out of the upper nipple when you pull that hose?! I had a little bit last time around, but this time the stuff just keeps flowing out! Not just dripping, either. We're talking steady stream.
I finally popped the hose back on and left it just now to see what you guys thought. Is everything just under too much pressure? Pulled th radiator cap hoping that would defuse the situation a bit, but no dice.

Ideas? I can't have coolant steadily flowing from whatever opening the whole time I'm working, that's just a giant mess!
HALP!