On 2 Oct 2004 18:19:14 -0700, (Bob Olds) wrote:

That fuel punp fitting must have a nut to clamp down on the "O" ring.
This compresses the "O"ring and locks the fitting in place.

That nut is only used on fittings that have to be adjustable ...
typically 45 and 90 degree. The straights, IME, don't have one.