Without a brake line flare, you’re tempting fate. Driving without proper flaring can cause leaks in the brake line, limiting hydraulic pressure and causing brakes to fail. However, flaring a brake line requires a capable brake flaring tool that limits poor or inconsistent flaring, possesses durability, and has all the necessary components to get you back on the road quickly.
At a Glance: Our Top Picks for Brake Line Flaring Tools
- BEST OVERALL : Eastwood 45 Degree Double & Bubble Flaring Tool
- RUNNER-UP: OTC 6502 Master Brake Flaring Tool Kit
- BEST BUDGET OPTION: GEARWRENCH Bubble Flaring Tool Kit
Comparison of the Best Brake Line Flaring Tools
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Brake Line Flare Types
Low-pressure hydraulic systems may use a single flare, but these can often leak and cause compression fittings to come apart. Therefore, nearly all vehicles now use a double flare or bubble flare on brake lines to ensure a tight, long-lasting fit.
Double Flare
Also known as an SAE flare or inverted flare, a double flare is a suitable choice for brake lines and the industry standard in both North America and Asia through the 1980s. Think of it as a bubble flare that’s folded over again, hence the name double flare.
Bubble Flare
Popular in Europe but also found on cars manufactured worldwide since the 1990s, a bubble flare, or ISO flare, gets its namesake from the “bubble” that appears at the end of the brake line. Many mechanics and auto enthusiasts describe a bubble flare as a double flare that’s done only half-way. This is because the bubble flare is formed using only the first of the two steps normally done to create a double flare.
What Makes a Great Brake Flare Tool?
To make a perfect brake line flare that’s strong and impervious to leaks, you need the right tools for the job. Yet not all brake flare tools are created equal. They come in varying budgets and quality standards, but the price isn’t the only determinant in what makes a reliable brake flare tool. When you’re researching or purchasing a brake flare tool, look for these characteristics that ensure a well-done brake flare with every use.
Ease of Use
Great brake flare tools provide exceptional ease of use. Not only are they portable and lightweight, but they also have all the tools you need to create a brake flare. For the novice mechanic, decent brake-flare tools will provide a professional quality flare in a matter of minutes without any headaches. Plus, many of these also come with step-by-step instructions to keep problems to a minimum.
Both Imperial and Metric Measurements
Both imperial and metric measurements are necessary for an above-average brake flare tool. This is especially handy for people who own multiple cars from different countries. Imperial measurements are perfect for American-made cars, while metric measurements work on nearly all European and Asian makes and models.
Able to Flare any Material
Before buying a brake flare tool, users should attempt to find the type of metal used in their car’s brake lines. However, this isn’t always possible due to severe rusting or corrosion. Thankfully, a solid brake flare tool takes the guesswork out of the equation. These tools come with all of the components needed to flare all types of metal, including stainless steel, soft steel, brass, aluminum, copper, and more.
Creates Multiple Flare Types
Depending on the use and scope of the project, versatility is essential. That’s why buyers should look for brake flare tools that have the ability to make multiple types of flares, including single, double, and bubble flares. In addition, tools that can flare fuel and transmission lines also add to the flexibility, usability, and overall value..
Eastwood 45 Degree Double & Bubble Flaring Tool
Review of the Best Brake Line Flaring Tools
Tools can make a drastic difference in the amount of time and ease necessary to complete any automotive repair. To this effect, brake line flaring tools are no different. However, some are better than others.
With the seemingly limitless number of brake line flaring tools available on the internet or automotive stores, selecting the correct one can feel daunting. To make your decision simpler, here are some of the top-rated brake line flaring tools.
PROS
CONS
What Does This Flare Tool Include?
Vise Mounted Brake Flaring Tool
Lever Handle
Blow Molded Case
Rotating Die Head – Features “operation 1” and “operation 2” dies for 3/16”, 1/4”, 5/16”, 3/8” and 4.75mm, 45 degree, double flares
Sets of Split Dies – for 3/16”, 1/4”, 5/16”, 3/8” and 4.75mm
What Type of Flare Job is This Best For?
The Eastwood 45-Degree Double and Bubble flaring tool is ideal for all types of brake lines. Thanks to its design and durability, it’s easy to use on all types of metals, making a perfect flare regardless of the hardness of the metal. In addition, the process of creating flares takes only a few minutes, making it ideal for quick repairs.
Should I Choose a Different Option on This List?
If you require push-connect style flares, such as those commonly found on brakes, this tool won’t work. It only makes single, double, and bubble flares. In addition, some novice users may find that the instructions are for more experienced individuals, creating frustration.
Bottom Line
Durable, straightforward, and versatile, this brake line flaring tool checks all the boxes for both beginners and veteran mechanics. Despite the need to take the brake line off the vehicle and the need for a vise, the Eastwood is still one of the top-rated brake line flaring tools, providing quality flares time after time.
PROS
CONS
What Does This Flare Tool Include?
Flaring bar
Arbor press
Adapters
Tube cutter
Deburring tool
Hard case
What Type of Flare Job is This Best For?
The OTC 6502 Master Brake Flaring Tool Kit has practical applications for any type of brake flaring done at home. Plus, this flaring kit can also create flares for fuel lines and AC lines, making it more versatile than some of the other options available.
Should I Choose a Different Option on This List?
For users that need flaring for hydraulic lines on tractors or farm equipment, better options are available than the OTC. Some users also report that the flaring tool creates burrs around the clamps that require additional deburring, filing, or sanding afterward.
Bottom Line
Although the OTC does require additional deburring, the affordability and ease of use make it a winner among other brake flaring tools. Durable, professional-grade construction also makes it a tool that will last longer than cheaper options.
PROS
CONS
What Does This Flare Tool Include?
Metric bar assembly
Yoke assembly, reamer
47 mm flaring tool adapter
6 mm flaring tool adapter
8 mm flaring tool adapter
10 mm flaring tool adapter
What Type of Flare Job is This Best For?
With four different metric flaring tool adapters, the GEARWRENCH Bubble Flaring Tool Kit makes both bubble and double flaring a cinch. This flaring tool is also a great choice for beginners due to its ease of use.
Should I Choose a Different Option on This List?
If you’re using imperial measurements, another option would suit as this flaring kit only contains metric flaring adapters. The unit contains poor instruction for bubble flaring, requiring users to do research regarding this type of flare. Also, the kit doesn’t work on stainless steel brake lines.
Bottom Line
For metric double flares, the GEARWRENCH Bubble Flaring Tool Kit will get the job done. However, those searching for a kit that uses imperial measurements, provides bubble flare instructions, or offers solutions for stainless steel brake lines should look elsewhere.
PROS
CONS
What Does This Flare Tool Include?
- Vise assembly
- Internal deburring tool
- Depth plug
- Grease
- Forming die
- 1/4 & 4.75, forming die 3/16
- Plastic case
What Type of Flare Job is This Best For?
The Lisle 33260 Flaring Tool is consistently rated as one of the top options for double flares. Because it’s designed specifically for double flares, these flares are often more precise than other flaring options.
Should I Choose a Different Option on This List?
With few adapters, those that have several types of brake lines to flare will either have to purchase more adapters or choose a different flaring tool kit.
Bottom Line
For quick, easy double flares, the Lisle 33260 Flaring Tool is perhaps the best option available on the market. However, buyers that want more versatility in a flaring tool may not find this item as useful as others.
PROS
CONS
What Does This Flare Tool Include?
- Universal Hydraulic Flaring Tool Assembly
- 17 pc. Dies
- 19 pc. Adapters
- Convenient Storage Case
What Type of Flare Job is This Best For?
Thanks to its versatility, the Ares 18010 Universal Hydraulic Flaring tool can do numerous types of flares and lines. On top of brake lines, this kit can also handle transmission cooler lines and fuel lines in all types of metals.
Should I Choose a Different Option on This List?
Buyers will have to pay a higher price for the convenience of a hydraulic flaring tool.
Bottom Line
With multiple uses, a squeezable hydraulic handle, and more dies and adapters than other kits, the Ares 18010 Universal Hydraulic Flaring Tool is an excellent choice.
PROS
CONS
What Does This Flare Tool Include?
- Flaring tool
- Op1 punch
- Op2 punch
What Type of Flare Job is This Best For?
The ARES 18025 Flaring Tool is specifically designed for double flares on 3/16-inch tubing. However, this size is the most common type of brake line found on American and Asian vehicles, making the tool useful for most home-use automotive care.
Should I Choose a Different Option on This List?
If you need to create any type of flare other than a double flare, this tool won’t work for your needs. It’s also only for use on 3/16-inch tubing, meaning that users will need to buy a separate tool for different sized brake lines.
Bottom Line
For those with the need to flare 3/16-inch tubing in steel, copper, or nickel, the ARES 18025 Flaring Tool should suffice. However, the unidimensional applications of this tool may require buyers to find more flexible and useful options.
Common Brake Line Flaring Problems
Although many manufacturers design brake line flaring tools with simplicity and ease of use in mind, you may run into some common problems along the way. Some of these issues are the result of improper brake line prep while others may be the result of a lack of experience.
One of the most common problems is a lopsided or uncentered flare. Most often, this occurs because the user of the flaring tool doesn’t have the right amount of tubing exposed prior to the first step of the flaring process
Another issue that arises when flaring brake lines deals with 45-degree and 37-degree variants. Also known as the Army-Navy flare (AN flare), the 37-degree flare requires different tools or adapters. These two types of flares are not interchangeable.
Some of the other problems include failing to replace rusty tubing, improper filing and deburring prior to inserting the flaring device, or using a tool other than a tube cutter to cut the tubing.
How to Use a Brake Line Flaring Tool
Flaring a brake line is simple if you follow step-by-step instructions via printed directions or a video. If you’ve never flared brake lines, here’s a straightforward way to complete the process with your brake line flaring tool.
- Use a tube cutter to cut a section of the brake line. Don’t use a hacksaw or any other type of tool, which can crush the metal.
- Deburr the inside of the tubing.
- File the end for a smooth finish.
- Add the flare nut onto the brake line.
- Use the adapter provided to determine how much tubing length to expose.
- Clamp the tubing into place.
- Tighten the yoke onto the tubing with the adapter until it stops.
- Remove the yoke.
- Put on the next flaring adapter and retighten yoke.
- Remove yoke, and you should have a centered, clean, flared brake line.
If you need any more context or a visual interpretation of brake flaring, refer to the video below:
And remember, practice makes perfect.
Conclusion
With numerous brake line flaring tools, selecting just one is the most difficult part. If you need brake line flaring, make sure to determine how often you’ll use it, your level of patience, and your budget. Using this guide, you’ll find the ideal brake line flaring tool to suit your needs.
People Also Ask
Although you now know how to flare a brake line, you may have some other questions or concerns that may occur before, during, or after the process. Here are some of the questions that beginners or those new to brake line flaring often ask.
How to Flare Brake Line Without a Tool
Flaring a brake line without a flaring tool is possible, but it’s unsafe and highly dangerous. Even experienced mechanics rely on flaring tools to complete the process. Not only are flaring tools inexpensive, but they’re also far more precise and reliable than any other type of flaring method.
How to Double Flare Brake Lines
The double flare brake line process is outlined above. However, you should make sure that the brake line you’re flaring is indeed a double flare and not a bubble flare. This will ensure that everything fits together without leaks.
How Tightly Do You Fasten Double Flare Brake Line?
To avoid crimping or crushing the brake line, tighten it by hand. Then tighten it to the OEM torque spec given by your manual. If one is not available, get a flare wrench on it, make it *snug*, then give it another 1/16th turn.
Lisle 33260 Flaring Tool
What Size Flare Nut Wrench For Brake Lines?
In general, American cars use a 7/16 flare nut wrench for brake lines. Imports use 10, 11, 12, and 13-millimeter flare nut wrenches. But unlike a regular wrench or a crescent wrench, a flare nut wrench won’t squeeze or pinch the brake line. This ensures that the brake line evenly distributes hydraulic pressure to the brakes without any leaking.
What Type of Flare is Used on Volvo Brake Lines?
Like most other types of European-made cars, Volvo uses bubble flares on its brake lines. The replacement and flaring of these brake lines will also require metric flare wrenches and a metric flaring tool.
Do Brake Lines Need to Be Double Flared?
Brake lines don’t have to be double flared; they can also have a bubble flare. However, both of these flares provide advantages over single flares. Namely, these types of flares drastically reduce the chance of leaks, as well as stand up to the heavy hydraulic pressure found in today’s brake systems.
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