The Shimano Ultegra BR-R8070 [paid link] hydraulic disc brakes are renowned for their exceptional performance and reliability in road cycling. Proper installation, meticulous adjustment, and regular maintenance are crucial to ensure optimal braking efficiency and safety. This comprehensive guide provides detailed instructions on installing, adjusting, and maintaining the BR-R8070 [paid link] disc brakes.
Tools Required
- 5 mm Allen wrench [paid link]
- Torque wrench [paid link]
- Shimano bleed kit [paid link]
- Mineral oil [paid link] brake fluid
- Isopropyl alcohol
- Clean, lint-free cloths
- Plastic tire lever or piston press tool
- Shimano TL-BH62 hose cutting tool (if hose trimming is necessary)
Installation of the BR-R8070 [paid link] Disc Brakes
Mounting the Calipers
- Prepare the Frame and Fork: Ensure that the frame and fork are compatible with flat-mount disc brake calipers. Clean the mounting surfaces to remove any debris or contaminants.
- Attach the Caliper: Position the caliper onto the mounting points of the frame or fork. Insert the appropriate length caliper fixing bolts through the caliper and into the mounting holes. Hand-tighten the bolts initially to allow for adjustment.
- Align the Caliper: Squeeze the brake lever gently to center the caliper over the rotor. While holding the lever, tighten the caliper fixing bolts to the specified torque of 6–8 N·m using a torque wrench [paid link].
Connecting the Brake Hose
- Measure and Cut the Hose: Route the brake hose from the caliper to the lever, ensuring it follows a smooth path without sharp bends. Mark the hose at the appropriate length, allowing some slack for handlebar movement. Use the Shimano TL-BH62 tool to make a clean, perpendicular cut.
- Install the Connector Insert and Olive: Slide the olive onto the hose, followed by inserting the connector insert into the hose end. Ensure the insert is fully seated to prevent leaks.
- Attach the Hose to the Caliper: Insert the prepared hose into the caliper’s hose connection port. Tighten the flare nut to a torque of 5–7 N·m.
Bleeding the Brake System
- Prepare for Bleeding: Remove the brake pads and insert a bleed block into the caliper to prevent the pistons from moving. Attach the Shimano bleed funnel to the bleed port on the lever.
- Perform the Bleed: Fill the funnel with Shimano mineral oil [paid link]. Open the bleed nipple on the caliper and allow fluid to flow, ensuring no air bubbles remain in the system. Close the bleed nipple securely once bleeding is complete.
- Finalize the Process: Remove the bleed block, reinstall the brake pads, and ensure the rotor spins freely without rubbing.
Adjustment of the BR-R8070 Disc Brakes
Brake Lever Reach Adjustment
The BR-R8070 levers feature reach adjustment to accommodate different hand sizes:
- Locate the Reach Adjustment Screw: This screw is situated on the inside of the brake lever body.
- Adjust the Reach: Use a 2 mm Allen wrench [paid link] to turn the screw clockwise to decrease reach (bringing the lever closer to the handlebar) or counterclockwise to increase reach.
Caliper Alignment
Proper caliper alignment ensures even pad contact and prevents rotor rubbing:
- Loosen Caliper Bolts: Slightly loosen the caliper mounting bolts so the caliper can move freely.
- Align the Caliper: Squeeze the brake lever firmly to center the caliper over the rotor. While holding the lever, tighten the caliper bolts to the recommended torque.
Maintenance of the BR-R8070 Disc Brakes
Regular Inspection
- Brake Pads: Check pad thickness regularly. Replace pads if the friction material is worn down to 0.5 mm or less.
- Rotors: Inspect rotors for signs of warping, cracks, or excessive wear. Replace rotors that are below the minimum thickness specified by Shimano.
Cleaning
- Brake Pads and Rotors: Keep pads and rotors free from oil, grease, or other contaminants. Clean them using isopropyl alcohol and a clean cloth. Avoid touching braking surfaces with bare hands.
Brake Bleeding
Perform a brake bleed at least once a year or if you notice spongy lever feel
- Prepare the System: Remove the wheel and brake pads. Insert a bleed block into the caliper.
- Attach Bleed Tools: Connect the bleed funnel to the lever and a drain hose to the caliper bleed nipple.
- Bleed the Brakes: Open the bleed nipple and gently pump the brake lever to expel air bubbles. Close the nipple once air is removed and lever feel is firm.
Troubleshooting Common Set-Up Issues
Spongy Brake Lever
A spongy or soft brake lever often indicates air in the hydraulic system:
- Solution: Perform a thorough brake bleed to remove any trapped air.
Brake Noise or Squealing
Noise during braking can result from contamination or improper pad bedding:
- Solution: Clean the rotors and pads with isopropyl alcohol. Ensure proper bedding-in of new pads by performing several controlled stops from moderate speed.
Rotor Rubbing
If the rotor rubs against the brake pads:
- Solution: Realign the caliper by loosening the mounting bolts, squeezing the brake lever to center the caliper, and retightening the bolts to