77 CHEVY VAN (Trans line)
Reply #1 –
Is this a standard "flare" fitting on the line, with a captured nut that screws onto the fitting on the rad? It's quite possible the flare on the line has already been compressed to fit the previous fitting (is this a new rad?) and has no more "squishability" in it to adapt to a new position, no matter how straight.
You can try cutting and re-flaring the tube to get a nice new surface, and/or put in a new fitting that hasn't been deformed yet.
Plus, instead of just installing and cranking it down as tight as you can the first time, loosen and re-tighten it 4-5 times to allow the two surfaces to "bed in" to each other. This also works for fittings that use copper or aluminum gaskets.