I need to hook some -AN fittings up to the factory (or possibly in the future, new) fuel lines. What are tube nuts, tube sleeves, and how does it all go together?

Here's a picture of a tube nut and a tube sleeve. When you order them, you specifiy the AN Fitting Size and the tube size.

 

just slide the sleeve, as they call it, on the line and tighten the nut down on the mating part and it crushes the sleeve to make a seal.

 

No, you have to flare the line after putting the nut and sleeve on.

 

oh yeah i forgot that part, it's been a while since i did it. you'd of known real quick if you got it wrong.

 

Cool, thanks, that's what I needed to know!