Fuel line cap for Mark IV

I am having trouble finding the screw caps that hold the fuel line and “olive” onto the fuel pumps. The fuel line has an outer diameter of 5/16 inch. I called SU and they sent me caps with a 3/8 inch opening and a fitting for the end of the fuel line. Does anyone know the part number or source for the 5/16 inch part?

Can you identify the thread from this chart? I think it is 1/4 BSPP.
10-1009.pdf (153.8 KB)

I actually have all of the materials to make the connection in your picture, and I may just do the same thing. The original used an “olive” instead of the piece at the end. This would require the same cap with a 5/16 hole. The only difference to me, is that with the curved gas line the fitting does not push on all the way. If I over come this issue, I assume the end is soldered on?


Yes, the end fitting is soldered on. I wonder, maybe they didn’t have compression olives back in the '30s?

Thank you for the information. Right now the connections near the gas tank (5) are with olives. If I use the tip pieces at the fuel pumps, that would at least get the fuel line connected.


Found it, Paul Beck Vintage Supplies. They have 5/16" nuts and olives.


They also have those solder end fittings that mine has.

It was some other kind soul on this forum that made me aware of this vendor; might have been Ed, who has helped me with a lot of other things.


  Thank you for the information.  I did order a number of the

fittings. I believe I may clean up the original caps to use where
they show, the back is tapered. I am missing just a few that are
hidden underneath. The prior owners of my car threw out the 2
fuel pumps and put one in the back of the car reducing the number
of fittings. This is a very minor problem, when you understand
that they also threw out the engine transmission and front seats.

Thanks for your help,