Rev Up Your Automotive Smarts

DIY Brake Line Extension: A Comprehensive Guide for Enhanced Safety

At a Glance

  • Whether you’re tackling a minor repair or embarking on a major overhaul, understanding how to extend brake lines is crucial for ensuring a safe and reliable braking system.
  • If necessary, use a brake line bender to shape the brake line to fit the desired routing.
  • If the brake system fails to operate after extending the brake lines, there may be a problem with the installation or a separate issue within the brake system.

Extending your brake lines is a necessary modification for various automotive projects, including custom vehicle builds, suspension upgrades, and performance enhancements. Whether you’re tackling a minor repair or embarking on a major overhaul, understanding how to extend brake lines is crucial for ensuring a safe and reliable braking system. In this comprehensive guide, we’ll delve into the intricacies of brake line extension, providing step-by-step instructions, safety precautions, and expert tips to empower you with the knowledge and confidence to complete the task effectively.

Safety Precautions

Before embarking on any brake line work, it’s imperative to prioritize safety. Brake fluid is highly corrosive and can cause severe skin irritation. Always wear protective gloves and eye protection during the entire process. Additionally, never smoke or work near open flames, as brake fluid is flammable.

Materials Required

To extend brake lines, you’ll need the following materials:

  • New brake line (length determined by the required extension)
  • Brake line flaring tool
  • Brake line bender (optional)
  • Double-flaring unions (male and female)
  • Brake fluid
  • Bleeder wrench
  • Torque wrench

Step-by-Step Instructions

1. Measure and Cut the Brake Line

Measure the required length of the brake line extension and cut it accordingly using a tubing cutter. Ensure a clean and perpendicular cut to prevent leaks.

2. Flare the Brake Line

Using the flaring tool, create a double flare on one end of the brake line. The flare should be smooth and symmetrical, with no cracks or imperfections.

3. Install the Double-Flaring Union

Insert the flared end of the brake line into the female double-flaring union. Tighten the union securely using a torque wrench to the manufacturer’s specifications.

4. Bend the Brake Line (Optional)

If necessary, use a brake line bender to shape the brake line to fit the desired routing. Avoid sharp bends or kinks, as these can weaken the line and compromise its integrity.

5. Install the Brake Line

Install the extended brake line into the vehicle, connecting it to the existing brake system. Ensure all fittings are tightened to the manufacturer’s torque specifications.

6. Bleed the Brake System

Once the brake line is installed, bleed the brake system to remove any air that may have entered the lines during the extension process. Use a bleeder wrench to open the bleeder valve on each caliper or wheel cylinder and allow the air to escape.

7. Check for Leaks

After bleeding the brake system, inspect the entire length of the brake line for any leaks. If any leaks are detected, tighten the fittings or replace the damaged section of the brake line.

Troubleshooting

Brake Line Leaks

If you encounter brake line leaks, check the tightness of all fittings and unions. If the leak persists, the brake line may be damaged and require replacement.

Spongy Brake Pedal

A spongy brake pedal can indicate air in the brake lines. Re-bleed the brake system to remove any trapped air.

Brake System Failure

If the brake system fails to operate after extending the brake lines, there may be a problem with the installation or a separate issue within the brake system. Seek professional assistance immediately.

Advanced Techniques

Using a Brake Line Kit

For more complex brake line extensions, consider using a pre-made brake line kit. These kits include all the necessary components, including pre-flared brake lines, unions, and fittings, to make the extension process easier and more efficient.

Custom Brake Line Fabrication

For unique or challenging vehicle builds, custom brake line fabrication may be necessary. This involves bending and flaring brake line tubing to create custom lengths and shapes. Specialized tools and experience are required for this advanced technique.

Wrap-Up: Extending Your Brake Lines with Confidence

Extending brake lines is a crucial skill for automotive enthusiasts and professionals alike. By following the steps outlined in this guide and adhering to safety precautions, you can confidently extend your brake lines to meet the specific needs of your project. Remember, a properly extended brake line ensures a safe and reliable braking system, which is essential for the performance and safety of your vehicle.

What You Need to Know

1. What type of brake line should I use?

Use DOT-approved steel or stainless steel brake lines. These lines are designed to withstand the high pressure and corrosive nature of brake fluid.

2. How much brake line should I extend?

Measure the difference between the original brake line length and the required length. Add a few inches of extra length for flexibility and ease of installation.

3. Can I use a single flare instead of a double flare?

No, double flares are required for brake line connections. Single flares are weaker and can leak under high pressure.

4. How tight should I tighten the brake line fittings?

Tighten the fittings to the manufacturer’s torque specifications. Overtightening can damage the fittings or the brake line.

5. How often should I inspect my brake lines?

Inspect your brake lines annually for any signs of rust, corrosion, or damage. Replace any damaged brake lines immediately.

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Cars have been my passion from a young age as I enjoyed learning how engines work, spending hours dreaming about the supercars I hoped to own, and I now have my dream job as a product designer for a luxury automaker. In my spare time I love going to car...