Ford Repair: Power steering 99 taurus SE, power steering fluid, resevoir

Question
i don't know if you can help me but lets try. When the engine is off i checked the power steering fluid level and it was fine. But when you start the engine and check the psf levels you find that the fluid was all sucked into the pump. So i filled the resvoir to required level(engine still running). But when you shut off the engine the resvoir quickly fills up and eventually shoots out the top. So when the engine is off the power steering resevoir is full to the very top of the resevoir but when you start it all that fluid gets sucked into the pump causing it to be low. You can not add more because it will all shoot out when engine is shut off. Thanks for your help in advance.

Answer
Adam-

 Ideally this is what should happen.  When the engine's off the fluid will sit in the pump but once the engin'es running the pump is circulating the fluid through the steering rack and the associated lines.  It's like watching a radiator when the car is warmed up...the level will appear lower since the coolant is flowing through the engine and if you fill it back to the top you'll have too much liquid in there when the coolant returns after the car is shut off.  Hope this helps.

Steve