How to Bleed Hydraulic Disc Brakes - SRAM®

Introduction

This tutorial will guide you through the process of bleeding SRAM hydraulic disc brakes using the Park Tool BKD-1 Bleed Kit. Proper brake bleeding is essential for maintaining optimal performance and safety in your bicycle's braking system. Following these steps will help ensure you can effectively remove air from the brake lines and restore brake function.

Step 1: Bicycle Preparation

Before starting the bleeding process, prepare your bicycle to ensure a safe and effective procedure.

• Secure the Bicycle: Place your bike on a work stand or ensure it is stable and upright.
• Remove the Wheel: Take off the wheel with the brake you are bleeding for easier access.
• Clean the Area: Use isopropyl alcohol and a rag to clean around the brake caliper and lever to avoid contamination.
• Position the Brake Lever: Ensure the brake lever is parallel to the ground for a proper bleed.

Step 2: Bleed Kit Preparation

Prepare your bleed kit and tools to get ready for the bleeding process.

• Gather Tools and Materials:
  • BKD-1 Hydraulic Brake Bleed Kit (DOT)
  • PP-1.2 Hydraulic Brake Piston Press
  • Hex and Torx-compatible wrenches
  • NP-6 Needle Nose Pliers
  • Zip ties
  • Toe strap or similar
  • Torque wrench
  • Isopropyl alcohol and rags
• Assemble the Bleed Kit: Follow the instructions specific to the BKD-1 kit to set it up properly.

Step 3: Bleeding the Brakes

Now it’s time to begin the bleeding process.

• Insert the Bleed Port: Use a hex wrench to remove the bleed screw from the brake lever, then insert the appropriate fitting from the bleed kit.
• Fill the Syringe: Fill the syringe with the specified brake fluid (DOT fluid) and attach it to the bleed port.
• Open the Caliper Bleed Port: Remove the bleed screw from the caliper using a hex wrench.
• Attach the Second Syringe: Connect another syringe filled with brake fluid to the caliper bleed port.
• Create Pressure:
  • Squeeze the brake lever to push fluid through the system.
  • Watch for bubbles in the fluid; this indicates air being expelled.
• Close the Ports: Once bubbles cease to appear, close the bleed ports while maintaining pressure in the system.
• Remove Syringes: Carefully detach the syringes and replace the bleed screws securely.

Step 4: Resetting the Bicycle

After bleeding the brakes, reset your bicycle for normal use.

• Reinstall the Wheel: Place the wheel back onto the bike, ensuring it is secure.
• Check Brake Function: Squeeze the brake lever to test for firm resistance; this indicates successful bleeding.
• Torque Settings: Use a torque wrench to ensure all screws are tightened to the manufacturer’s specifications.

Step 5: Clean the Bleed Kit

After completing the process, clean your tools to maintain their longevity.

• Clean Syringes and Tools: Use isopropyl alcohol to clean all syringes and tools used in the bleeding process.
• Store Properly: Organize and store the bleed kit and any other tools used for future use.

Conclusion

Bleeding your SRAM hydraulic disc brakes is crucial for maintaining performance and safety. By following these steps, you can ensure that your brakes function optimally. Remember to regularly check your brake system for air bubbles and fluid levels to keep your ride safe and enjoyable. If you encounter any issues, consulting a professional mechanic may be beneficial.