I have the same problem ... want to replace the P.S. pump, but haven't figured out how to remove the pump's pulley so it can be transferred to the new pump. How did you remove the pulley; does it use normal or left-hand threads?Mine did that suddenly recently, but was accompanied by horrible pump dyng sounds. I think something busted inside the pump that caused cavitation.
Rebuilt PS pump from Advance Auto for $110 fixed me right up. Replace all fluid while at it.