cant get replacement 3/8 fuel hose to fit

[PalmSprings]

(note : my use of the letters "FL" below ,means" a std rubber fuel injection 180 psi .3/8" fuel hose or line )

Im replacing my fuel hoses.

The new 3/8 FL wouldnt go on no matter what,including pre boiling,spray siliconing,light greasing. I am now trying hand screwing in a threaded bold to stretch the FL even slightly. I dont expect much because of the rubbers tendency to return to its original shape is very strong.
The old 3/8 FL was stretcthed enough,but it had been on the rv for several years . I dont plan on letting my new ones stay" bolted "that long so theyll fit.
I have asked several auto parts places and they dont have FL larger than 3/8.
Ive spent alot of google time and found nothing.

Has anyone run into this issue before and if so how was the hose expanded or where was a larger than 3/8 FL found?
My choices for larger sizes are 7/16 or 1/2" FL. I would hope that would work IF they can be found.
Any info,ideas?

[Nick-B]

Hi Palm Springs,

I'm guessing your coach is a gas Ford chassis and I would expect it to have 3/8" fuel line on it. First verify that the rubber hose is actually 3/8". I mean actually measure it if you have the means to.

Also you mention "180 psi" fuel injection line. Rubber hose rated that high may be too stiff for your fittings. If you have the Ford chassis, your fuel injection system is normally only operating at 40 psi. You could safely use 100 psi hose which should be a bit more flexible - that said, the 180 psi hose "should" fit anyway.

Somethin' ain't right!

[wildtoad]

This may not help but I had a similar problem when researching my gen fuel pump issue. I took the existing hose off the existing pump, cut 1/2 inch off as the ends were going bad and tried to reconnect them. Would not go. Lubed, stretched, etc and would not go without deforming. Got a new fuel pump and a new filter and went to hook them up to the existing hose (and some new) and they went on without a hitch. I can only surmise from this that the old pump was either just a bit larger as in not to spec (it too was an aftermarket) or there was some left over residue on the ends preventing the tubes from slipping on properly.