When you say pressuring the pump wasnt pressurizing it was "pumping" the pump pushes fluid in and out of the gear box and sometimes it takes more fluid to go from one side to the other. The pump runs off the serpentine belt so the faster the motor the faster the pump turns therefore when its running all the extra fluid will go into the resivoir. There is usually a relief valve to make sure it doesnt pump to fast. That could of went bad as well.
Id keep a eye on it and get worried if you look in and all the fluid is gone.
Heres a diagram I found
Howstuffworks "How Car Steering Works"