Power Steering Pump Question

[COLEFORBUS]

I have replaced 2 power steering pumps because they are leaking from what looks like where the pump attaches to the reservoir. I went to a different part store for the third one. When the power steering fluid leaks I mean it pours out and the reservoir is empty within a couple hours. The steering gear is new, the lines are new, and the leak is not coming from the lines. It drips straight down from the pump. I am wondering if I am mounting it wrong or if maybe the parts store I bought the first two from sells from a manufacturer that doesn't put them back together properly.

[ajsfirehawk]

I just did a pump replacement on my 72 C20. I had the new pump, and had to remove the reservoir from the old pump and install the new pump in the old reservoir. The pump is surrounded by the reservoir and it has two O-rings that go between the pump and the inside of the reservoir in the back and one large one in the front that goes all the way around the pump casting to seal it to the reservoir in the front. Are you installing the reservoir or buying the unit pre-assembled?

[COLEFORBUS]

Yea the first two were preassembled remanufactured ones from advance auto parts. I got the one I have now rom O'reilly. It may not be much better