1998 ford taurus power steering?

[lovebeautifultahiti]

I'm replacing the power steering pump on my 1998 ford taurus. It is still leaking after the replacement, and I think it is because I didn't install the white teflon O-ring. First, why would this ring make it leak, since it doesn't seem like it really does any thing. Second, how do I install the white teflon O-ring? It doesn't seem to fit in the hole on the power steering pump, and I can't figure out where it goes. Oh, this is for the high pressure hose, not the return hose. Please help me out!

Thank you and merry Christmas!