You can install a "spring" inside the hose, loose fit is fine to ease installation, or outside if your situation dictates. A screen door spring will work and can be stretched to space out the coils. Some tool gypsies sell them, made of soft wire to make stretching easier.

I think this one is meant to go on the outside of the hose:
https://www.aquatuning.us/water-coo...20sZFUDXcaYyrGtRyOq1eO4rl6xoCi3IQAvD_BwE

I am pretty sure that vacuum hose is different from fuel line, rubber wise. It seems to me that use with fuel vapor affects the rubber differently than does liquid. Anyone have the real information on that?

Mac :{)

1962 K10 short step side, much modified for rally
1969 T50 fire truck, almost nos, needs a few things