How to Make Your Own Custom Brake Lines

  • 2-4 hours
  • Intermediate
  • 50-75
What You'll Need
Blank length of brake line
Steel tubular line cutter
Ball peen hammer
Flaring vice
Die for flaring
Flare driver
Well-lit work area
Jacks and blocks for under-vehicle work

On older cars, you will sometimes need to make custom brake lines as the size you need may no longer be in stock. Use the original brake line as your measuring guide to create your own custom brake line, following the process below.

Step 1 - Raise Your Vehicle Off the Ground

Use a series of properly mounted jacks to support the vehicle frame, braced by blocks so you can get under the vehicle safely.

Step 2 - Remove the Original Brake Line

Carefully detach the original brake line from all its slip mountings and straighten it out, to measure its exact length.

Step 3 - Obtain New Blank Brake Line

Take the original brake line to the auto supply shop to purchase new brake line. It should have a steel mesh outer cover and be lined with PTFE, usually called Teflon. Purchase new blank brake line 3 inches longer than the original so you can fit it correctly the first time. Brake lines cannot be stretched.

Step 4 - Cut the Brake Line to the Length Desired

Use the brake line cutter to cut 1 inch off the piece of brake line purchased. To use the line cutter, slip it onto the brake line to where the cut is needed, brace it with 1 finger, and twist the cutting wheel downward to the cut line. When it is secured in place, rotate the cutting wheel till it goes all the way through the line. Remove the fitting off the excess portion. You can tap it gently with a ball peen hammer to release it.

Step 5 - Prepare the Brake Line for Flaring

Attach the fitting on the end of the brake line where you will create the flare. Be sure the flex-nut faces the line on the inside section. Set the line with fitting aside, and get the flare tools.

Step 6 - Use the Flare Vice and Die to Make the First Flare

Undo the screw on the flare vice to open it. Insert the brake line into the flare vice to the correct diameter. Tighten the flare vice so the line becomes the desired thickness for the flare die.

Step 7 - Attach the Central Fitting Over the Stainless Steel Line

Slip the central smallest fitting over the PTFE inner hose line. The flared part of the fitting will go over the outer stainless steel shell.

Step 8 - Affix the Top Part of the Fitting to the Line End

The third part of the fitting now goes over the central fitting, making a liquid-tight compression of the inner PTFE hose.

Step 9 - Attach the Fitting to the Other End of the Brake Line

Repeat this flaring process at the other end of the brake line, attaching the fitting in 3 parts as shown in Steps 7 and 8.

Step 10 - Install the New Brake Line

Following the exact path of the original brake line, insert the new brake line into your vehicle. Use new couplings and fasteners to attach it to the chassis to prevent scratches and kinks.