Technical How on earth do I flare steel tubing for fuel lines?!

we don't want to go there again!

I find 3/8" isn't too difficult, but getting the flare centered on small 3/16" tubing can be challenging.

 

Nope, check this story out : https://www.jalopyjournal.com/forum/threads/fuel-shut-off.646790/#post-7175003

 

Buy the US made NiCop, I bought some off Amazon from a US based seller, but it was imported- it was ****. Buy the SUR&R line that is made in the USA- watch out they sell import as well.

 

I like using stainless, it looks best and last forever. A tip on flaring any steel lines is to cut the tube with a band saw or hack saw not a tubing cutter. The latter work-hardens the steel and that can make for blow outs (splits in the flare) and sloppy, leaky unions. After cutting on a fine tooth saw I file flat, debur inside and out, anneal slightly and use the Eastwood flaring tool and SS fittings. Then a fast trip to the polishing wheel.

Personally, I use 6-AN (37 degrees) on all my fuel systems and inverted double flare on brakes (45 degrees).

 

Then I’d be looking for fittings to make it work again!

 

Oh yeh, don't forget to put the fitting on (the right direction) before flaring!

 

The most sure way to make sure you make a perfect flare is to forget the fitting.

 

I think the reason for double flare is the pressure contained in the system . Single flare is fine for fuel line pressure . I worked in LPG industry for years , no double flare , single flare copper is code .

 

I should have added that one of the reasons I purchased a hydraulic tool was I was building a complete truck every year and a half or so. I wanted to work the best that I could so getting a better flaring unit made sense. It wasn't cheap so for those that only use one once or twice, it wouldn't be the best use of funds.

 

Are you sure you didn’t accidentally buy stainless steel tubing? The trouble you are having sure sounds like it.

 

Manual flare tool needs to be old and USA, might try tape around where you clamp it or put the whole ***embly in a vise. If you're going to just use a fuel hose and worm type clamp on it then use the die for the double flare and just make a bubble/bulge. A single or double flare with a fuel hose ****s to push on, might damage the inside of the hose and isn't really needed. Cut with a die grinder or hacksaw, hand file straight, de burr outside and inside.

 

Or forget to put it on……

 

That’s what I was thinking

 

I also have that Mastercool tool. It works great 99% of the time. Once in a while the tube will slip, then I'll wrap it with tape as @theHIGHLANDER does.

 

Years ago I scored a great deal on a
Mastercool Universal Hydraulic Flaring Tool – 45° Double & Single Flares, Push Connect, GM Fuel Line, Brake Line & GM Transmission Cooling
It was on Ebay over 200 mi. away and for pickup only. It just so happened that I was leaving on trip that put me within 5 mi of the guys place. I've never regretted that buy

 

I bought a Snap On kit back in the eighties and it still works great. I’ve never had a problem with the tube slipping out, though I’ve had to cut off and redo many times. I always double flare however I can’t remember the last time I went bigger than 5/16”.

To prevent the end from cracking, I always deburr the tube with a small countersink, then by rubbing it on a piece of sandpaper in a figure eight pattern.

The Snap On tool might be a little snug because when I use the copper nickel stuff it gets a bit scored around the cir***ference, the steel not so much.

 

There are hard and soft steel and stainless steel tubing always buy the soft tubing, polish the cutoff / remove all the burs and then use a flairing tool

 

this is what I have been using, almost goof proof perfect flares every time . No down time by fixing mistakes,no leaks. Not cheap ,super easy to use, just follow the correct colour and number , remember to put the tube nut on first ,ha ha. No hydraulics ,just a simple cam and lever.

 

I used double wall galvanized steel tubing, 3/8" for the fuel lines I'm running in my truck, double flared with an antique military flaring rig. Will these hold at high pressure? Its what they had at local auto parts store. Anybody have experience with this potential mistake?

 

I've Mastercool hydraulic kits in both 37 and 45, I was in the right place at the right time when they became available. All brakes down here need to be DOT approved, no AN or NPT fittings. I've used these on aluminum, SS and steel without issue

 

I've still got my SnapOn double flare tool that I bought in the early 70's if not the mid 60's when I was in trade school. It needs a new correct size pin on the hinge end though. I also have the Eastwood Hydraulic as I had a bunch of projects planned when I bought it.
The only tubing I have had trouble flaring was/is that Green coated straight lengths that the parts houses sell now. I also bought the Eastwood deburring tool and it cleans up the ends and cuts as Billy said he does. Not inexpensive but for me it makes things go smoother.
As far as size goes I have had better luck with 3/8 tube than 3/16 brake lines over the years.