[luigirox]

ok im am realy frustrated I have tried to run 5/8 full line with a 5/8 return and all my flare conntections leak. I am using copper flares nuts ends. I have tried over and over to reflare them. help?

[rbinck]

Are the lines copper? I used steel tube and Swagelok industrial tube fittings. They use a double ferrule. Parker is another brand. I went from tube to MPT screwed into a FPT to barbed fitting for the flex hose. Been installed since '96 with no leaks.

I'm not sure how the copper tube fittings would work, but they are rated for a lot of pressure even brass fittings on copper tube.

[luigirox]

I ment brass fittings

[rbinck]

What is the tube material?

[luigirox]

The tube is aluminum

[rbinck]

Oh wow. I have no idea about aluminum. You might try getting some brass inserts and use a ferrule type fitting. I don't think I'd be using aluminum tube myself, too soft.

[The Greek]

Aluminum is fine for fuel line. With this type of material you should use 37 degree single flare A-N fittings. Regular automotive flare fittings require the use of a 45 degree double flare. Aluminum doesn't work well with a double flare. Double flares are for steel tubing. The aluminum "Work Hardens" when it is sharply bent and when double flared, have a tendency to crack at the flare. If not double flaring, is it possible that you are using the wrong flaring tool with the wrong angle to the flare? Most brass flare fittings are for 45 degree double flares and steel tubing.