Are you looking to upgrade your vehicle’s braking system? Installing stainless steel brake lines is a common and effective way to improve brake performance.

How to flare stainless steel brake lines  is a crucial skill for anyone working on automotive repairs or modifications. Flaring creates a leak-proof connection between the brake line and the fittings, ensuring the safe and efficient transfer of hydraulic fluid. Whether replacing damaged brake lines or customizing your vehicle, mastering the art of flaring stainless steel brake lines is essential for optimal braking performance and safety.

In this guide, we will walk you through the step-by-step process of flaring stainless steel brake lines, equipping you with the knowledge and skills to tackle this task confidently and precisely. Let’s dive in!

What Will You Need?

Before we start, ensure you have all the necessary tools and materials for the job. Here’s a list of what you’ll need:

• Stainless steel brake line
• Brake line flaring tool (single or double)
• Tubing cutter
• Deburring tool
• Pliers or vice grips
• Brake line fittings
• Pipe thread sealant or Teflon tape

Once you have everything you need, we can move on to the flaring process.

9 Easy Steps on How to Flare Stainless Steel Brake Lines

Step 1: Measure and Cut the Brake Line

Use the tubing cutter to carefully measure and cut the stainless steel brake line to the desired length. Ensure the cut is clean and free of jagged edges, as a smooth cut is essential for creating a proper flare. Double-check your measurements before cutting to avoid wasting material or making errors in the brake line length. Ensure that you have enough extra length to accommodate the flare.

Step 2: Deburr the Edges 

After cutting the brake line, use a deburring tool to smooth out the edges of the cut. This step is crucial as any burrs or jagged edges can compromise the integrity of the flare and lead to leaks. Insert the deburring tool into the end of the brake line and rotate it until the edges are smooth and even. Take care not to remove too much material, as this can affect the fit of the flare. Proper deburring ensures a clean, uniform surface for the flaring process. Remember to deburr both the inside and outside of the brake line.

Step 3: Select the Flaring Tool and Die

Choosing the appropriate flaring tool and die is crucial for achieving a professional-grade flare on the brake line. Various types of flaring tools are available, such as single flare, double flare, and bubble flare tools. The type of flare required depends on the specific brake system and the fittings used. Consider the following factors when selecting the flaring tool and die:

• Type of Flare: Based on the specifications of your brake system, determine whether you need a single flare, double flare, or bubble flare.
• Compatibility: Ensure that the flaring tool and die are compatible with the size and material of the brake line you are working with.
• Quality: Look for a well-constructed, durable flaring tool that provides consistent and reliable flares.
• Ease of Use: Consider the flaring tool’s ease of use and comfort, as these can impact the overall flaring process.

Take your time to research and select the appropriate flaring tool and die that suits your specific needs. A well-chosen tool will ensure accurate and secure flaring, leading to a safe and reliable brake system.

Step 4. Proper Technique and Preparation

Achieving precise and secure flares requires proper technique and preparation. Here are a few essential steps to follow:

• Line Preparation: Ensure the brake line is clean and free from dirt, debris, or rust. Use a deburring tool to remove any sharp edges or burrs that may affect the quality of the flare.
• Secure Clamping: Use a suitable clamping device to firmly secure the brake line, preventing any movement during flaring. This ensures consistent and accurate flares.
• Lubrication: Apply a small amount of lubricant to the flaring tool’s cone and the brake line fitting. This reduces friction and facilitates smooth flaring.
• Proper Depth: Adjust the flaring tool’s depth to ensure the flare’s desired length. This is crucial for proper compatibility and a secure connection with the brake system.
• Uniform Pressure: Apply consistent and uniform pressure while operating the flaring tool. This helps create even and symmetrical flares, ensuring a reliable fit between the brake line and the fitting.

Step 5: Single Flare

If you are using a single flare tool, follow these steps:

• Place the brake line into the flaring tool’s clamp, ensuring it is secure.
• Insert the flaring cone into the brake line until it reaches your desired depth.
• Apply firm pressure to flare the brake line around the cone, creating a 45-degree angle flare.
• Remove the flare from the flaring tool and check for imperfections or unevenness.

Step 6: Double Flare

For a double flare, follow these steps:

• Place the brake line into the flaring tool’s clamp, ensuring it is secure.
• Press down on the flaring tool handle to push the flaring cone into the brake line until it reaches your desired depth.
• Use a countersink punch or similar tool to create a slight depression in the center of the flare, which will prevent cracking.
• Apply firm and even pressure to continue creating the double flare.
• Remove the flare from the tool and inspect for any imperfections.

Step 7: Bubble Flare

For a bubble flare, follow these steps:

• Place the brake line into the flaring tool’s clamp, ensuring it is secure.
• Push down on the flaring tool’s handle to insert a cone-shaped die into one end of the brake line.
• Use a countersink punch or similar tool to create a slight depression in the center of the flare, which prevents cracking.
• Press down on the handle to continue flaring, creating a convex shape at the end of the brake line.
• Remove the flare from the tool and check for any imperfections.

Step 8: Testing

After completing all necessary flares, testing them for accuracy and reliability is essential. Install the fittings onto each end of the brake line, ensuring they are secure and tight. Then, use a pressure tester or manually apply pressure to ensure no leaks in your new flares. If there are any issues, carefully inspect the flares and make necessary adjustments or repairs.

Step 9: Finishing Touches

Once you have confirmed that your flares are secure and leak-free, you can install the brake line onto your vehicle. Properly connect and tighten the fittings, ensuring they are in their correct positions. Finally, bleed the brakes to remove any air bubbles and ensure proper functioning of the brake system. Don’t forget to regularly clean and lubricate the fittings to maintain their integrity and prevent corrosion.

By following these steps, you can achieve precise and reliable flares on your brake lines, ensuring a safe and efficient braking system for your vehicle.

5 Things You Should Avoid

When it comes to flaring stainless steel brake lines, certain pitfalls should be avoided to ensure a successful and reliable installation. Here are five essential things to steer clear of:

1. Using the Wrong Tools: Using proper tools for flaring stainless steel brake lines can lead to accurate flares and compromised connections. Use specialized flaring tools for stainless steel lines to ensure precise and secure flares.
2. Insufficient Tube Preparation: Please prepare the tube before flaring to ensure strong and complete flares. It’s essential to ensure that the tube ends are clean, deburred, and free from any imperfections that may affect the quality of the flare.
3. Over-Tightening Flare Fittings: Over-tightening flare fittings can damage threads, crack fittings, or distort flares. Follow the manufacturer’s recommendations for torque specifications to ensure a proper and leak-free connection.
4. Ignoring Proper Flare Angle: The flare angle is crucial in establishing a reliable seal. Neglecting the correct flare angle can result in leaks or weakened connections. Be sure to adhere to the specified flare angle for stainless steel brake lines.
5. Skipping the Inspection Process: After flaring stainless steel brake lines, it’s essential to thoroughly inspect the flares for any signs of cracks, distortions, or imperfections. Skipping this step can lead to faulty connections and compromised brake system performance.

By avoiding these common mistakes, you can ensure a safe, reliable, and effective flaring process for stainless steel brake lines, promoting optimal braking performance and overall vehicle safety.

Conclusion

How to flare stainless steel brake lines requires precision, patience, and attention to detail.

By following the recommended practices and avoiding these five common mistakes, you can successfully install stainless steel brake lines that will provide reliable braking performance for your vehicle. Remember always to use the proper tools, prepare the tube correctly, adhere to torque specifications and flare angles, and thoroughly inspect your flares before installation. With these precautions in mind, you can confidently tackle flaring stainless steel brake lines for a safer driving experience. 

So, be mindful and careful while working with stainless steel brake lines to ensure a successful installation process. Stay safe on the road!