14' should be plenty, but there's been some question earlier in the thread about that tubing having a high enough temperature rating. It's not designed for diesel fuel, it's designed for air brakes.

 

I know the fuel can get hot but I doubt it's going to be enough to melt the tubing. I've been running that boost gauge tubing in my engine bay for almost 5 years now and I've never had a problem with it. Not to mention how hot the air is once it's compressed.

 

BigBlue, you're running this air line tubing here?

 

Been using it for boost gauge tubing for years now. I was just saying that it's been under my hood for almost 5 years in extreme heat/cold, and has had hot air pushed through it for 5 years and I haven't had any problems with it. I doubt you'd have any issues at all running that stuff. Heck, I've got some lying around. I'll put it in a pot of boiling water and see how long it takes before it melts. How's that sound?

 

Think about it though. Safety wise, air brake lines MUST be designed to resist fuel and grease, or there are some dangerously unsafe rigs out there!

The tubing will be fine, if you are afraid, do like I did and slide it though a section of real Fuel hose, that has to be heat and oil resistant, right?

 

I have always used 1/8 copper cappilary tubing for oil pressure gauge line with vacuum tubing over it. Will copper tubing work for diesel fuel, or is there some oxidation, heat transfer, or other issue to stay away from copper? Thanks