What hose is this?

98 Jimmy, there are metal lines that run down the top of the frame rail on the driver's side, beneath the rear door. What is the outermost one?

98 Jimmy, there are metal lines that run down the top of the frame rail on the driver's side, beneath the rear door. What is the outermost one?

We need a good picture of it.
Where does it go to?

This sounds like the gas lines, running from the tank to the engine, but a picture for sure, would help to answer this one.

If it's the same as my 2000 Jimmy it is the brake line for the rear brakes. I just replaced mine that's how I know. There is a 6" section of those lines that gets a lot of road dirt that just sits there and rots the lines out. Now that I fixed my brake line, my fuel line is leaking...

Yep, rear brake line, thanks. A chunk of it came off in my hand while I was under there yesterday...tried to trace it but it seemed to just end in the middle of nowhere. I remember now that when I bought it there was a rear brake leak that the PO fixed, so this must be the original rotten line.