This line was hanging off my truck when I parked it. I took a look and for the life of me cant figure out where it came from. Its near the front differential near the right passanger wheel.

I wiped some dirt off the line and it said FUEL. The truck starts but im just not sure what this thing does or where it goes. It could be useless for all I know.

 

Looks like a vent line for your rear diff.

 

Thank you very much! I feel so silly but no pictures I could find said anything about it.

Thats what it is, says I just need to hang it back up out of sight

 

Yep, put the end up as high as you can. Usually it routes along the gas filler neck, on most vehicles.

 

Looks like this vent line is for the front differential - anyone recall where that one runs?

 

Passenger side fender well or firewall???

 

Yeah, mine just runs up onto the fender well, almost directly above the axle.