Shimano Deore BR-MT520/BL-MT501 Hydraulic Disc Brake System User Manual

Introduction

This manual provides essential information for the proper installation, operation, and maintenance of your Shimano Deore BR-MT520/BL-MT501 Hydraulic Disc Brake System. This system is engineered for robust performance and a rigid design, suitable for various cycling disciplines from cross-country to trail riding. The BL-MT501 brake levers feature Servo Wave technology for responsive initial pad contact, and are compatible with I-spec II shifters. They are paired with powerful BR-MT520 4-piston calipers, designed to enhance braking confidence and control.

Image 1: Shimano Deore BR-MT520/BL-MT501 Hydraulic Disc Brake System, showing both the lever and caliper components.

Setup and Installation

Proper installation is crucial for the safe and effective operation of your hydraulic disc brake system. If you are unsure about any step, it is highly recommended to seek assistance from a qualified bicycle mechanic.

Tools and Materials Required:

• Hex wrenches (various sizes)
• Torque wrench
• Brake hose cutter
• Barb and olive insertion tool
• Shimano mineral oil
• Shimano bleeding funnel and oil stopper
• Clean rags and isopropyl alcohol
• Protective gloves and eyewear

Installation Steps:

1. Mounting Levers (BL-MT501): Attach the brake levers to your handlebars. Ensure they are positioned for comfortable reach and operation. The BL-MT501 levers are I-spec II compatible, allowing for integrated mounting with compatible shifters. Tighten the clamp bolts to the manufacturer's specified torque.
2. Mounting Calipers (BR-MT520): Secure the BR-MT520 calipers to your frame/fork using the appropriate mounting adapters for your rotor size. Ensure the caliper is centered over the rotor. Tighten mounting bolts to the specified torque.
3. Hose Routing and Cutting: Route the hydraulic brake hoses along your frame, ensuring they do not interfere with steering or suspension movement. Cut the hoses to the appropriate length, ensuring a clean, square cut. Install new barbs and olives into the hose ends.
4. Connecting Hoses: Connect the hoses to the brake levers and calipers. Tighten the hose nuts securely, but do not overtighten.
5. Brake Fluid Filling and Bleeding: Fill the system with Shimano mineral oil and perform a brake bleed procedure to remove any air bubbles. This typically involves attaching a bleeding funnel to the lever reservoir and using a syringe at the caliper bleed port. Refer to Shimano's official technical documentation for detailed bleeding instructions.
6. Pad Installation: Ensure the brake pads (D02S metallic pads are commonly supplied) are correctly seated in the calipers.
7. Lever Reach Adjustment: Adjust the brake lever reach to suit your hand size and preference. This is typically done via a small screw on the lever body.

Image 2: Close-up view of the Shimano Deore BL-MT501 brake lever, highlighting the ergonomic design and adjustment points.

Operating Instructions

Once installed, proper operation ensures optimal performance and safety.

Bedding-in New Brake Pads:

New brake pads and rotors require a bedding-in process to achieve full braking power and consistent performance. This involves a series of moderate to firm stops to transfer pad material to the rotor surface. Perform approximately 20-30 stops from a moderate speed (e.g., 15-20 mph) without coming to a complete stop, allowing the brakes to cool between efforts. Avoid hard, prolonged braking during this period.

Braking Technique:

• Apply both front and rear brakes simultaneously for balanced stopping power.
• Modulate braking force by gradually increasing pressure on the levers. Avoid sudden, hard braking unless in an emergency.
• In wet or muddy conditions, braking performance may be reduced. Apply brakes earlier and with more caution.
• Be aware of your weight distribution. Shift your weight backward during heavy braking to prevent being thrown forward.

Maintenance

Regular maintenance ensures the longevity and reliable performance of your Shimano Deore disc brakes.

Routine Checks:

• Brake Pad Wear: Regularly inspect brake pads for wear. Replace pads when the friction material is less than 0.5mm thick or if they show signs of contamination (e.g., oil, grease).
• Rotor Condition: Check rotors for excessive wear, bends, or contamination. Clean rotors with isopropyl alcohol if contaminated. Replace if worn below minimum thickness or severely damaged.
• Hose and Connections: Inspect hydraulic hoses for any signs of damage, kinks, or leaks. Ensure all connections are secure.
• Lever Feel: If the brake lever feels spongy or pulls to the handlebar, the system may require bleeding to remove air.

Cleaning:

Clean calipers and rotors regularly with a clean cloth and isopropyl alcohol. Avoid using harsh chemicals or lubricants near brake components, as this can contaminate pads and rotors, leading to a loss of braking power.

Brake Bleeding:

Over time, air can enter the hydraulic system, or the mineral oil can degrade. A full brake bleed should be performed periodically, or whenever the lever feel becomes inconsistent. Refer to Shimano's official service instructions for the complete bleeding procedure.

Image 3: Close-up view of the Shimano Deore BR-MT520 4-piston caliper, showing the robust construction and pad access.

Troubleshooting

This section addresses common issues you might encounter with your hydraulic disc brake system.

• Loss of Braking Power:
  • Cause: Air in the hydraulic system. Solution: Perform a brake bleed.
  • Cause: Worn brake pads. Solution: Inspect and replace pads if friction material is low.
  • Cause: Contaminated pads or rotor (oil, grease). Solution: Replace contaminated pads and clean rotor thoroughly with isopropyl alcohol.
• Squealing Noise:
  • Cause: Contaminated pads or rotor. Solution: Clean rotor, replace pads.
  • Cause: Improper bedding-in. Solution: Re-bed the brakes.
  • Cause: Loose caliper or adapter bolts. Solution: Check and tighten all mounting bolts to specified torque.
• Spongy Lever Feel:
  • Cause: Air in the hydraulic system. Solution: Perform a brake bleed.
  • Cause: Low brake fluid level. Solution: Check fluid level and top up, then bleed.
• Lever Not Returning Fully:
  • Cause: Sticking caliper pistons. Solution: Clean pistons and apply a small amount of mineral oil to the piston seals (refer to Shimano service manual).
  • Cause: Contaminated or degraded brake fluid. Solution: Perform a full system flush and bleed.

Specifications

Warranty and Support

For detailed warranty information and technical support, please refer to the official Shimano website or contact your authorized Shimano dealer. Warranty terms and conditions may vary by region and product.

Official Shimano Website: bike.shimano.com