GM-GMC: power steering, power steering pump, gmc sierra

Question
i have a 1993 gmc sierra v6 4.3L and i need to know if i have to replace my whole power steering pump because i am leaking power steering fuild at the bottom of the pump and right behind the belt and it is only leaking when i start the truck and in the i might have lost in the about an 1 oz of power steering fuild in 10 min and when i turn the truck off it would quit leaking i need to know if i have to replace the whole pump or not
also this truck has been sitting in my driveway for the past year and has not started in the past 6 months if that could be anything to do with it thank you for your help in this matter  

Answer
My only suggestion is that you have some one look at it who can tell where exactly it is leaking and see if there may be a seal or something that is minor. I know that usually if there is a leak they replace the whole pump. Also the power steering pump leaking would have nothing to do w/ a no start condition. I'm a visual mechanic so if I can't see it I can't really help.