Learn me replacement fuel lines for really obscure car (flare types questions)

I'm slowly chipping away at my project Suzuki Cappuccino, which has morphed from a refresh into more of a restoration. I’ve replaced every part of the fuel delivery system between tank and fuel rail except the longest runs of metal hard lines, the ones that go under the floor and ironically were the least rusty, crusty part of the system.

The problem is that closer inspection reveals rust under enough of the clamping points that patching the rusty spots isn’t viable, and given that everything else is new, I’d rather not reuse them and be on borrowed time.

Every transition from metal to rubber uses a clamp with this type of end on the metal line.

A little Googling seems to indicate that this isn’t made with a garden variety flare tool, and that I might be able to buy bulk line with this flare on one end, but I need it on both ends at a specific length.

I can buy new lines in Japan for $23ish each and then pay shipping on a box probably 6 feet long or so…$ouch!

I think Classic Tube can probably replicate it, but there still the cost/hassle of boxing to ship all the way across the country, which is more expensive and perilous than it used to be.

On an EFI car I might be able to get away with the closest standard equivalent tubing with some sort of flare on the end for the return, and certainly the EVAP, but wouldn’t that be risky on the supply side?

Any other suggestions?

So that's basically just there to keep the clamp from slipping off, right? You could probably do a normal double flare and get the same effect. There's nothing magical about a hard fuel line.

Keith Tanner said:

So that's basically just there to keep the clamp from slipping off, right? You could probably do a normal double flare and get the same effect. There's nothing magical about a hard fuel line.

This.  Done it a bunch of times 

Thanks for the tips. It seems to me like the rounded-burnish flare on the end is to keep the hose and clamp from slipping off, and the inner bubble portion provides a guide to ensure one doesn't slip the hose on too far. The clamp goes between. I'm more used to compression nuts or banjos on the EFI supply side, so it is encouraging to hear that others have used a double flare and had good results.

Are the pictured lines the ones you're saying aren't salvageable? Honestly, they look great to me.

Perhaps rather than a flare, a bead tool is what you're after?

Generally, i like a bubble flare and double clamp with efi rated gates green stamped hose for doing this. The green stamped stuff seems to live waaaaay lo ger these days. I know theres a certain spec denoted by the green, just don't know what it is. 

And your understanding of the flare and ring is absolutely correct. 

In reply to obsolete :

The photos show the top of firewall/engine bay end...it is the other end that is not so great. Not sure I have a photo of the exact trouble area, but this line is from another six inches rearward and gives you an idea: 

j_tso said:

Perhaps rather than a flare, a a bead tool is what you're after?

That would be the correct tool to duplicate what the original line did. A partial double flare would work fine for keeping a hose from sliding off, although it's a little harder to start the hose. I would only worry about getting the exact copy of what the factory did if you were using some sort of quick-disconnect fitting or the like.

Bulk rolls of tubing ordered; should give me enough to get my eye in on the flaring tool with some practice scraps, plus extra for a future project or in case I screw up!

Eew, yeah those lines got to go.

I usually use the first stage of a double flare, with the line chucked in to the vise halfway as deep as it should be.  I usually have to make one or two test pieces to get the depth just right.  Full depth makes the flare too large to slip the hose over.

I've done it before too with a partially formed bubble flare.  The mastercool hydraulic flare tool makes easy work of this.  Instead of forming the second bead an inch down, use glue lined heat shrink as a hose stop. 

In reply to shuttlepilot :

Awesome idea: thanks for the tip! So much simpler than all the ideas I was mulling over!

Reading this with interest since rusting brake lines are pretty common here. I tried like 20 times and could never get a double flare straight with the standard auto parts stores' flare tools. Is the mastercool hydraulic flare tool really "the answer"? Like plug n play, no finesse? It may well be worth the $300!

Whatever you choose to do with the tube, be sure to use proper fuel injection hose clamps.

P3PPY said:

Reading this with interest since rusting brake lines are pretty common here. I tried like 20 times and could never get a double flare straight with the standard auto parts stores' flare tools. Is the mastercool hydraulic flare tool really "the answer"? Like plug n play, no finesse? It may well be worth the $300!

Yes. Follow the instructions and every single effort with the Mastercool will produce a good result. There is no luck or finesse needed. 

I have found it completely worth the money and have never regretted it. Plus it does way more than double flares. I had accumulated three or four lesser tools over the years which I gave away when I got the Mastercool.

In reply to P3PPY :

Yes, Yes it is!  I have had one for over 10 years and I would say my failure rate on making leak free flares is under 2%. IF you de-burr the cut end and make sure it's square to the tubing you almost can't fail using this tool. In your case I like to use the die for making F.I. crimps in a line.  Like Ford has used for years. I just don't go "all the way" on making it so that the tube is only buldged out.  I then cut the tube back an inch or so, so that the buldge is at the end of the line.

In reply to Cousin_Eddie (Forum Supporter) :

Indeed.  Besides double and bubble flare, I've done 37 degree single flare (AN), GM thread in fuel filter (also works for some fuel rails, power steering lines), quick disconnect fuel lines, a brooch, a pterodactyl...