If you’re handling your own auto repair, you’ll need a brake flaring tool. Whether you’re doing maintenance or fixing up a project car, knowing how to properly flare brake lines is a must.
Flaring brake lines creates a leak-proof connection without any additional sealant, ensuring you won’t loose fluid that could put your brakes at risk of failure. In the long run, these tools can make a significant investment, saving you a trip to the repair shop.
In this guide, we’ll explore why brake flaring tools are so important for vehicle repairs — and how to use them step-by-step.
Why You Need a Brake Flaring Tool
A brake line flaring tool is indispensable when it comes to repairing brake lines. Instead of removing the brake line from your vehicle, the tool allows you to do your repairs while everything is still in place.
Owning a brake line tool can save you both time and money. Instead of calling in a professional to replace broken brake lines — or spending money on costly premade lines — you can take the repairs into your own hands.
A flaring tool is also easy to use. For experts and beginners alike, it doesn’t take much practice to get the hang of the system. Even the most complex designs only require a basic understanding of the process.
A comprehensive tool kit includes a positioning bolt, die lubricant, double-ended op1/op2 punch, and a flaring tool.
Other important features of a brake flaring tool include:
- Compact design for vehicles
- Removable handle
- 3/16 inch brake line to match most vehicles and trucks
- Can create a perfect 45-degree double flare
How to Use a Brake Flaring Tool
A brake flaring tool can make a powerful addition to your tool kit. That being said, you need to learn how to properly use it.
Our detailed, step-by-step guide will walk you through the process of brake line flaring your vehicle’s brakes quickly and easily.
1. Gathering the Tools and Materials
For every mechanical job, you need the right tools if you want to achieve the best possible results. Flaring steel brake lines is no exception.
There are a few different types of appliances used for flaring, including hydraulic, manual, and leverage manual. For most DIY projects, you’ll be using manual tools, which are the cheapest and the most user-friendly. While hydraulic and leverage manual brake line flaring tools can handle the job much faster, they’re also much more expensive and are only recommended if you need to make multiple flares in a day.
To make sure the outcome is consistent and accurate, always use the proper flaring tools. A double flare brake line kit should be easy to find — not to mention affordable.
Before committing to a kit, make sure you check the recommended fittings, flare nuts, brake line fluid, and sizes for your vehicle. You can find these in the owner’s manual or by checking the local auto shop.
Other tools you should have on hand include a tape measure, tubing cutter, gloves, and a tubing bender.
2. Cutting the Tubing
Once you have all your tools on hand, it’s time to get the tubing or brake lines ready for flaring.
Using the old brake lines as a guide, measure and cut each line to the desired length with a tubing cutter. While you can use a hacksaw, it’s not recommended for brake lines because the metal is weaker. If you do, make sure you carefully remove any burrs.
It’s critical that you make a perfect perpendicular cut to make sure that the flare turns out even.
3. Cleaning and Deburring
Next, remove any burrs until the cut edge of the tube is smooth. You can use a simple screwdriver to take care of the burrs, but the tubing cutter also has a blade-like structure for deburring.
When deburring, proceed slowly and carefully to avoid thinning the metal of the tubing. Thin tubing could lead to splitting when it’s put to use.
Once you’ve finished deburring, clean any metal parts on the end that’s been cut. This helps avoid any debris during the flaring process.
4. Slide the Fittings into the Tubing
The next step is to slide the fittings into the tubing. The fitting should be placed in such a way that the threading faces the side you’ve just cut.
As most lines are flared on both ends, you should ensure that you add two fittings, each pointing in opposite directions. Once this step is complete, your tube is ready for flaring.
5. Setting up the Tubing
Next, the tubing line should be loaded into the corresponding hole, and then the wing-nut clamps tightened to hold the line in place. While you can use your flaring tool without mounting it in a vise, a vise can make the process more manageable.
As you set things up, make sure the flaring tool hangs over the table’s edge, as the brake lines have to drop below the tool while you work. Leave about 1 to 2 mm above the flaring base.
Each double flare brake line kit comes with a set of dies. Before flaring, ensure that the die matches your tubing line — as each line size has its own matching die. The flaring tool’s wing-nuts should be tightened to firmly hold the tubing.
The final part of this step is to insert the die with the stub sliding into the brake line. The stub is designed to slide into the line to secure the die in place.
6. Make a Bubble Then Double Flare
Before the double flare, you’ll need to make a bubble flare. After everything is set, press the locks over the flaring tool’s base and the die. Thread the press down until the die touches the base and the press is tight. Then, remove both the press and die. At this point, you should notice a bubble on the line.
Finally, place the press over the line again — this time without the die — and thread it down. To avoid damaging the flare, make sure you don’t crank too hard — only until it’s tight. Then, you should have a completed double flare, giving you the perfect seal for your brake fluid. Make sure you check for splits, scoring, or imperfections in your flare before you wrap things up.
The Right Brake Flaring Kit For the Job
There’s no question that a brake flaring tool is a necessary part of any automotive tool kit. Not only does it allow you to replace your brake line yourself, but it can also help you perform a high-quality, professional-looking job from home.
Flaring a brake line requires a capable double flaring tool kit — something durable, consistent, and with all the components needed to get you safely back on the road.