How to bend and flare steel lines

Discussion in 'Wrenchin' Secrets' started by CJay, Sep 21, 2021.

  1. CJay

    CJay Supercar owner Staff Member

    I've been meaning to make a how to thread about this for quite some time. I'm going to do this in installments. I'll explain how to bend and flare, how to copy existing damaged lines and how to fabricate custom lines. I'll also share my tips and tricks along the way.

    First, let's start with the tools of the trade. Here's a selection of benders I have in my toolbox. They each have thier own applications. The bender on the extreme left is my "go to" bender for 90% of my lines. So here they are-

    20210921_172638.jpg

    And here are my flaring tools. The hydraulic flaring tool is awesome. It's a bit pricey but we'll worth it if you do alot of lines. The manual flaring tool works well, but requires alot of effort.

    20210921_172730.jpg

    Next installment we'll get into thw basics of bending
     

    Attached Files:

    JohnnyS, srb, JCP and 1 other person like this.
  2. 71stagegs

    71stagegs bpg member #1417

    Time to get that new craftsman bench dirty
     
  3. Fred Hickey

    Fred Hickey Founders Club Member

    Looking forward to refine my knowledge. Before getting involved in quality Buicks, I was/am in the contracting business and in winter we did snow removal. I have fixed more rotted brake lines, steering lines, and miscellaneous hydraulic lines. Usually in the middle of the night, in the cold on the snow. Looking forward to a gentleman's approach to such items.
     
    Lane in Mt.Hermon and CJay like this.
  4. Prairie Piston

    Prairie Piston Well-Known Member

    Wish I had this a few months (year?) ago. Copied existing lines the bends were pretty decent. I struggled a bit with the flares but because I used a cheap garbage set. It all worked out in the end.
    I did run into a flare? that I didn’t know how to do. It was about an inch from the end of the line….
     
  5. Gold '71

    Gold '71 '71 GS, Cortez Gold

    Those Mastercool hydraulic flaring tools are the best. I love mine.
     
  6. CJay

    CJay Supercar owner Staff Member

    So let's get into how I duplicate lines. In this first case, we have an existing line that we want to copy. I'll use this stage 1 furl line as an example. Your going to need a piece of 3/8" line linger than 36" for this.

    20210922_170136.jpg

    20210922_170916.jpg
    I usually start at the fuel pump end. The first bend is tricky because the bend is very close to the nut. In this case, we have to use the manual flaring tool because the die stocks on the hydraulic tool are too long.

    So the first thing your going to do is cut off the factory flare. We're going to use my go to bender and put a 90 degree bend in the line

    20210922_170859.jpg

    Now we install the nut and flaring bar and make a mark on the tube so we can cut the tube. We're trying to get the flare as close to the bend as possible

    20210922_171039.jpg

    Making a inverted flare is a 2 step process. First step is to use the die to crush the line.

    20210922_171350.jpg

    20210922_171409.jpg

    Next step is to use the cone to finish it off

    20210922_171435.jpg

    And there you have an inverted flare!

    20210922_171454.jpg
     
  7. CJay

    CJay Supercar owner Staff Member

    Now we have the flare made and the first 90 degree bend

    20210922_171537.jpg

    Next we have to make the second 90 degree bend up to the carb. First thing I do is fit the original line in my bender and make a pencil mark on the line where it enters the bender. This gives us a point of reference. I also make a pencil mark along the spine of the bend

    20210922_171617.jpg

    Now we transfer that mark to our new line

    20210922_171703.jpg

    Now we install the new line in the bender and line up the pencil mark to the bender. This ensures the new bend will be in the exact same location as the original.

    20210922_171750.jpg

    So you can see the second bend is identical to the original.

    20210922_171812.jpg

    So you just repeat the process on each bend, fitting the original in the bender. Marking the reference point on the line and making a line on the spine of the bend to orient the new line in the bender.

    Clear as mud so far?
     
  8. buickbill

    buickbill Well-Known Member

    the lines that are stocked locally here are made out of some b.s and dont flair .they just split .there used to be good lines .i dont know why they left
     
  9. Cutlass

    Cutlass Platinum Level Contributor

    Cool trick to use the bender to copy the geometrie!
     
    Lane in Mt.Hermon likes this.
  10. FJM568

    FJM568 Well-Known Member

    Nice write-up!

    Met you in the pits at the Nats this past year. I was pitted next to docgsx with my blue 66 Skylark in the circle track area.
     
  11. CJay

    CJay Supercar owner Staff Member

    Oh yeah!! Good seeing you!
     
    FJM568 likes this.
  12. CJay

    CJay Supercar owner Staff Member

    So getting back to our fuel line- so we're just working our way up the line, putting the original in the bender, transferring the pencil mark to the new line and putting in the bends...

    20210923_144009.jpg 20210923_144333.jpg

    You can put the original line up against the flat side of the bender to further ensure the new line is oriented correctly in the bender.

    So after we get to the last bend, we make a pencil mark at the flare of the original line. If your trying to be extra precise, add a little less than an 1/8" extra to compensate for the flaring tool crushing the line down a little.

    20210923_171655.jpg

    Now we'll use the hydraulic flaring tool to make the flare at the carb end. Same two step process but alot easier.

    First step

    20210923_171917.jpg

    And finish it up with the cone. And don't forget to put the nut on first!!

    20210923_172000.jpg

    And there you have it! A stage 1 fuel line thst cost $5 and took me about 15 minutes

    20210923_172419.jpg
     
  13. CJay

    CJay Supercar owner Staff Member

    Next installment we'll go over a few of the other tools to tweak and bend lines.

    I'll also go over some tips and tricks to fabricate custom lines too
     
  14. Buicksky

    Buicksky Gold Level Contributor

    I liked the product placement. Is Arizona Sweet Tea one of your larger sponsors ? ;)
     
    Dano and 69GS430/TKX like this.
  15. BUICKRAT

    BUICKRAT Got any treats?

    Jay, you really need to try the SUR&R flaring tool. For flares off the car, it is really the most precise and repeatable flaring tool made, and takes less than a minute to set up and flare a line.

    BTW, I love how clean your hydraulic tool is. When I use it to flare an existing line on the car, it's usually all covered in brake fluid and rusty chunks. Plus, it's a fiddlefu&k to work with trying to hold everything in place, the dies, the line, and the tool, and then try to tighten the setscrew without moving anything, not to mention getting the line at exactly the end of the die. Just being a realist here. haha
     
  16. Clarkie

    Clarkie Well-Known Member

    As soon as I saw this thread, I thought to myself, “This thread needs to be pinned.”
     
  17. CJay

    CJay Supercar owner Staff Member

    I'll have to check that one out! Yeah, I'm a neat freak with my tools. They get wiped down, wd-40'ed and put away after every job. The box gets wiped down with a damp microfiber rag and pledge :) I even pledge the challenger lol
     
    FLGS400 likes this.
  18. Max Damage

    Max Damage I'm working on it!

    I have had a bad experience with the cheap flaring tool you pictured above, it was a learning experience though. I found that you have to carefully debur and chamfer the tube end before using the flaring tool, or it goes badly.

    I wasted so much time and effort with that thing! Eventually I stepped up to Rigid Tool double flare tool, which is SO much better. Better grip on the tube, smoother action, perfect flares.

    Thank you Jason for taking all the time to share this great info! I think you misspelled "Fuel "at the beginning of post #6 oh and "longer" too.
     
  19. hwprouty

    hwprouty Platinum Level Contributor

    I'm thinking you started this thread to 'display' some of your cool sh@!...
    New bench, rebuilt vise, rare shifter handle!!

    Seriously I'm following this thread, always struggled with making lines... already ordered the bender you show ( the blue one )

    Thanks Jason!
     
  20. BUICKRAT

    BUICKRAT Got any treats?

    A spelling Nazi? Really? what is this, 4th grade?
     

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