HOW TO PROPERLY FLARE BRAKE LINE TUBING
                     HOW TO PROPERLY FLARE BRAKE LINE TUBING
Mark Sanford
Writer at Brake System
University providing advice, reviews and information on 
brake system components including 
brake line repair tips at brake system university /
brake line repair kit reviews at break system university
For anyone replacing their own brake lines, knowing how to properly flare 
them is a must. Flared connections are essential for maintaining an airtight 
seal that keeps contaminants out of the brake system. The following gives 
a few tips on flaring your own brake line tubing.
HAVE THE RIGHT TOOLS
You will need a brake flaring tool. There are a variety of different tools on 
the market, from cheap manual flaring tools to expensive hydraulic-
powered tools that make a broad range of flares. For most applications, 
you’ll just need a simple flaring tool capable of making single and double 
flares.
When it comes to cutting your brake line to size, a proper tubing cutter 
offers the best results. Other methods, like using a hacksaw or rotary 
cutting tool, can leave uneven cuts that lead to poor flares. You’ll also need 
a file or a tapered reamer to deburr the brake line tubing shortly after 
cutting. Some tubing cutters will have a built-in file just for this purpose.
KNOW THE RIGHT TECHNIQUES
Once you have the tools needed to make a proper flare, you’ll need to 
know what type of flare your brake line project calls for:
• Single flares, where the brake line is flared out only once, are common 
on low-pressure brake systems but not usually recommended for use on 
modern high-pressure brake systems.
• Double flares are common on modern domestic vehicles and 
recommended for high-pressure brake systems.
• Bubble flares are common on European and Asian vehicles. They look 
similar to double flares. In fact, it doesn’t take much effort to turn a bubble 
flare into a double flare.
Once you have your tools ready, follow the steps below to properly flare 
your brake lines:
1. Use the tubing cutter to cut the brake line tubing to the desired length.
2. File down any leftover burrs from the inside diameter of the line. Use 
compressed air to blow out any cutting debris.
3. Place the brake line fitting over the tube prior to flaring, otherwise, it’ll be 
impossible to slide the fitting over without cutting off the existing flare.
4. Insert the brake line into the flaring tool, making sure that the end of the line 
barely pokes above the flaring base. For double flares, make sure the line barely 
reaches the height of the flaring anvil.
5. Use the appropriate flaring die to flare out the brake line end. Be careful not to 
use too much pressure, as this can cause the flare to split apart.
6. Repeat the above for the other end of the brake line.
PRACTICE LEADS TO PERFECTION
Achieving the perfect flare takes time and practice, so don’t be disheartened if 
your first few efforts don’t go as planned. The best way to get good at flaring your 
own brake lines is to grab a few lengths of inexpensive brake line and start flaring. 
Once you have the technique mastered, you can confidently flare brake lines for 
your own vehicle.
About Brake System U
Brake System University is a micro site giving advice, reviews, and technical 
information on various brake system components like brake lines, brake 
line kits, and ABS sensors. Brake System University connects you to high 
quality, genuine brake system replacement parts including  replacement 
brake lines, replacement ABS sensors, replacement brake line kits that 
have been tested and reviewed by experts. If you want to replace any 
component of your brake system, then this 
site(https://brakesystems.autopartsu.com/) will helps you in choosing the 
right component. Brake System University connects you to trusted reviews 
and referrals to help you easily make a purchase decision.