Thank you! That answers alot on how the union bolt is stoping the PS fluid from seeping out between the union bolt & pressure line. My new powersteering unit didn't come with a new fitting, I think they just gave me an O-Ring and hope I somehow stick the O-Ring in the old fitting.
How the heck did you remove the circlips when the union bolt is on the PS line? It's such a tiny opening to work with!