It looks like you're missing a copper washer on the banjo bolt...anytime you take that fitting apart it's wise to replace the two washers with new, they are available at your local parts store...take the old one with you to get the correct size.
Like Jethro said, when tightening up flare line fittings you want to pull them up tight, then back it off about 1/4 of a turn than slam it tight again. You'll notice the wrench moves further each time you do this. It might take three or four times of doing this until the wrench ends up at the same spot each try, then you know the flare is fully seated.
Mike B
