Hi Jim, when I was doing some engine work on my '52 J ten years ago, I had disconnected the neoprene hose from the fuel pump and it seemed OK. About 3am the next morning my wife woke me up to tell me she smelled gas real bad and so did I. It had all leaked out and I had to go out the garage at 3am and hose everything down. Not only a dangerous mess but a lot of expensive gasoline lost. I don't remember what I did to cap it off. If you're just swapping the pump out, not big deal but if you're going have the pump off it for a while you'll want to cap it somehow.