Hagerty DIY: Flaring Brake and Fuel Hardlines

In this episode on Hagerty DIY, I’ll be walking you through flaring hardlines for brake or fuel systems.

Creating you own custom fuel or brake lines can create a very polished and subtle final touch to a project. Take a look at our previous DIY on Bending Hardlines for the step-by-step breakdown of creating custom-fitted lines.

For flaring lines you will need three special tools: a tubing cutter, deburring tool, and also the flaring tool. Typically, these can be rented from a local parts store, but if you are doing multiple flares for a project I recommend purchasing a good flaring tool. The Eastwood Professional Brake Tubing Flaring Tool is what I recommend, as it combines easy leverage with a simple two-step process to make even your first time flaring lines a success.

Determine the size of line you need for your project by checking a service manual or the fittings you are looking to connect.

Start by cutting the tubing to length with the tubing cutter. While it is possible to cut small tubing like brake lines with a hacksaw, I don’t recommended it; doing so will require extra steps to ensure the end of the tube is square and not distorted.

With the tubing at the proper length, use the deburring tool to clean the inner edge of the tubing. This prevents any small pieces of debris from interfering with the flare, which could cause sealing problems for the finished part.

The last step to prepare the tubing is ensuring that the fitting you need is on there.  Forgetting the fitting can create a beautifully flared tube that is nevertheless unusable because it cannot be attached properly.

With the tubing now ready for the flare, select the proper dies and clamp the tubing into your flaring tool. Then use the flaring dies to shape the tubing into the desired flare for your application.

Once the flare has been completed, blow out the tubing with compressed air or brake cleaner to ensure that no debris is in the line that could cause interference later. Happy tinkering!