How to Flare Brake Lines

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Flaring brake lines ensures a leak-proof connection without extra materials or sealants. If the brake lines aren't properly flared, you can lose fluid that will cause your brakes to fail. This article will explain how to flare your brake lines using single and double flares.

Steps

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    [1]
    • Cutters will cut round tubing squarely without causing burrs. You will have to remove burrs if you use a hacksaw. [2]
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    [3]
    • The instructions for both types of single flare tools are given below.
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    • Lower the cone down until it is centered over the tube's end.
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    Turn the advance screw to move the cone until the part of the tube being flared is firmly against the countersunk recess of the bar.
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    If the line is damaged at all, replace it with a new one.
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Method 1
Method 1 of 2:

Generating Tool

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    • On a generating flare tool, the flare is formed in the air instead of in the recessed part of the bar.
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    Check the manual for the number of revolutions needed for the flare size you need.
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    If you end up with any damage, even a hairline crack, toss out the brake line and try again with a new one.
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Method 2
Method 2 of 2:

Double Flaring Tool (New Standard)

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    [4]
    • Ensure the depth is equal to the edge of your tubing size insert.
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    [5]
    • Remove the insert and finish advancing the cone into the bell.
    • The bell shape of the tube forms the double thickness flare.
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Video

Community Q&A

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  • Question
    Can I use a single in an application where a double flare was used?
    Uglymug18
    Community Answer
    No. Double flare is used in high pressure ABS applications for a reason. A single flare is more likely to spit under high pressure, causing break failure.
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      Tips

      • Practice flaring lines with some inexpensive tubing before flaring your vehicle's brake lines.
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      • The Society of Automotive Engineers recommends double flaring for all hydraulic brake lines.
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      • There are three types of flares: single flares, double flares, and bubble flares.
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      Warnings

      • Consult your tool's user guide for specific instructions. Tools' instructions can vary from manufacturer to manufacturer.
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      Things You'll Need

      • Gloves and eye protection
      • Measuring tape
      • Brake tubing
      • Tube cutters or hacksaw
      • Single flare tool
      • Double flare tool

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      References

      1. ↑ https://www.youtube.com/watch?v=IpT3jEnmmRs
      2. ↑ https://www.hotrodhotline.com/md/html/flaring_brake_line_3.php
      3. ↑ https://www.youtube.com/watch?v=IpT3jEnmmRs
      4. ↑ https://robrobinette.com/flare_brake_line.htm
      5. ↑ https://robrobinette.com/flare_brake_line.htm
      6. http://www.hotrodhotline.com/md/html/flaring_brake_line_3.php

      About This Article

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      Reader Success Stories

      • Anonymous

        May 23, 2017

        "Awesome! I did it years ago, but could not remember just what to do."
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