Giant MPH Hydraulic Disc Brake System

Introduction

Congratulations on your purchase of the Giant MPH Braking System.

The Giant MPH Braking System is an affordable entry-level hydraulic disc brake product. It offers stronger braking power compared to existing fully mechanical disc brake products by utilizing a cable-actuated hydraulic mechanism.

Features

• This system uses brake levers compatible with mechanical brakes to control the hydraulic disc brakes, allowing the conversion of a fully mechanical brake setup to a semi-hydraulic brake without needing to replace the original brake levers.
• The cable-controlled master cylinder converts simple mechanical force into strong hydraulic braking power and a smooth feel.
• The balanced lever design allows users to easily and accurately adjust braking force.
• Maintains consistent braking power without fade during intense use on long and steep downhill sections.
• Achieves optimal performance in both wet and dry conditions.
• Integrated design with the Giant CONTACT AEROLIGHT stem.

Important Notes

Warning

• This cable-actuated hydraulic disc brake system is a sealed design that has undergone pressure testing. Unless otherwise indicated, do not loosen, remove, or adjust any screws or seals to prevent leaks or brake failure.
• Do not ignore any brake fluid leaks. If you notice any signs of leakage from this brake system, stop riding immediately and seek assistance from your local authorized Giant/LIV dealer.
• Before each ride, reconfirm that the brake system is functioning correctly.
• Brake rotors and pads must not be contaminated with any type of grease, as this will cause immediate brake failure. Unless otherwise indicated, do not apply any products to the brake system.
• Rotors and pads are consumables and will wear thin with normal use. Minor scratches on the rotor surface are normal. Check the condition of the rotors before each ride. If the rotor is significantly warped or has deep wear marks (i.e., thickness is less than 1.5mm), replace the rotor.
• During heavy braking, the rotor surface temperature can rise sharply. Do not touch to avoid burns. Do not spray any liquids to cool the brake system, as this can cause component damage. Always ensure brake components are completely cool before making any adjustments.
• Contaminated or worn pads should be replaced immediately. The minimum pad thickness, including the backing plate, must not be less than 2.7mm.
• In rainy or muddy conditions, braking performance will inevitably decrease, and noise will become more noticeable. However, performance will recover and noise will disappear once dry.
• Do not touch the rotor while it is spinning, insert fingers, or attempt any adjustments. This can cause serious injury.
• Persistent noise accompanied by reduced braking power may indicate contaminated pads or rotors. Seek assistance from your local authorized Giant/LIV dealer.

Specifications and Compatibility

Parts List

Diagrams illustrating the components of the Giant MPH braking system.

Brake Body

Depicts the central brake body with brake cable inlets, bleed ports, adjustment knobs, and lock screws.

Front Brake Caliper

An exploded view of the front brake caliper assembly, showing the caliper body, brake pads, bleed port, mounting screws, and an adapter for rotor size.

Rear Brake Caliper

Similar to the front caliper, showing the caliper body, brake pads, bleed port, mounting screws, and adapter.

Important Notes

Warning

The Giant MPH braking system is a cable-actuated hydraulic system. The brake body has several production-related sealing holes. These holes are sealed with corresponding special screws from the factory. The diagram below highlights these sealing points.

Under no circumstances should you attempt to loosen, tighten, or adjust these special screws.

If you find any leaks, corrosion, or damaged parts, stop riding immediately and contact your local authorized Giant/LIV dealer for assistance.

Failure to follow these precautions may result in sudden brake failure.

Operation

Warning

Insufficient braking power directly affects riding experience and safety. Before each ride, ensure both front and rear brakes are functioning correctly.

Before each ride, confirm that the brakes are working correctly.

• Pull the brake levers several times to feel the action. The brakes should respond promptly with a firm feel.
• Straddle the bike, firmly pull the brakes, and try to push the bike forward. The bike should remain stationary. If the bike moves forward, braking power is insufficient.

Note: If you are not confident about the braking power, seek assistance from your local authorized Giant/LIV dealer.

Maintenance

Basic maintenance involves checking the brake system after each ride. You can use a damp cloth to wipe off dust and sweat from the brake body, but do not use any liquids to clean the brake body, hoses, calipers, pads, or rotors.

Brake fluid degrades over time and with use, losing its properties. The MPH braking system requires regular maintenance and fluid changes to ensure long-term durability. It is recommended to change the fluid once a year with continuous riding.

Changing brake fluid requires specific technical skills and experience. Seek service from your local authorized Giant/LIV dealer.

Pad Replacement

Note: For long rides or endurance events, it's best to have an extra set of new brake pads. This section describes the correct replacement procedure. Assess your own technical ability before proceeding. Most importantly, perform this in a safe environment. When performing on-site maintenance/adjustments outdoors, always comply with local traffic laws and ensure you do not impede traffic. Perform in a safe, clean area and be mindful of your surroundings.

Parts and Tools Required

• 1x Genuine Giant MPH Brake Pad
• 1x Pliers
• 1x Caliper
• 1x Plastic tire lever

1. Remove the wheel.
2. Use pliers to straighten the tail of the caliper retaining pin and pull it out (Diagram A).
3. Pull out the old brake pads (Diagram B).
4. If for periodic inspection, use a caliper to measure the thickness of the old pads. The minimum allowable thickness is 2.7mm (including backing plate) (Diagram C).
5. Use a plastic tire lever to push the caliper pistons back into place (Diagram D).

Caution

If the pistons are very stiff, do not force them. After removing the pads, do not attempt to pull the brake lever. If you encounter difficulties, seek service from your local authorized Giant/LIV dealer.

6. Confirm the correct orientation of the new pads, place the spring between them, and install the assembly into the caliper from the top (Diagrams E & F).
7. Insert the new retaining pin and bend its tail 90° with pliers (Diagram G).
8. Reinstall the wheel, ensuring the hub aligns with the frame/fork dropouts. Tighten the thru-axle/quick release to the specified torque (Diagram H).

Pull the brake levers several times to seat the new pads. Test ride in a safe environment.

Caution

• After installing new pads, the brake lever pull may feel deeper than before. This is due to the caliper design. This will resolve after a few lever pulls. Normally, no adjustment to lever reach is needed after pad replacement. If this persists, seek service from your local authorized Giant/LIV dealer.
• After installing new pads or rotors, initial braking power requires a bedding-in period for optimal performance. Perform the bedding-in process in a safe environment.
• To properly bed in disc brakes, first ride at a controllable speed in a safe environment. Brake with slightly more force than usual, but not so much that you skid or lose control. Avoid locking the front wheel. Repeat this process several times; braking power should significantly improve, indicating the bedding-in is complete.

Giant Limited Warranty

GIANT warrants the GIANT MPH disc brake product to the original owner for a period of two (2) years from the date of purchase.

Assembly at Purchase

This warranty applies only to new products purchased from an authorized Giant/LIV dealer and assembled by that dealer at the time of purchase.

Limited Remedy

Except as stated herein, the sole remedy under this warranty or any implied warranty shall be, at Giant's sole discretion, the replacement of defective parts with parts of equal or greater value. This warranty is effective from the date of purchase, is non-transferable, and applies only to the original purchaser. Giant shall not be liable for any direct, indirect, or consequential damages (including but not limited to personal injury, property damage, or economic loss) arising from contract, warranty, negligence, product liability, or any other cause.

Exclusions

This warranty or any implied warranties do not cover:

• Normal wear and tear of parts when there is no assembly or material defect.
• Service performed by unauthorized Giant/LIV dealers.
• Modifications made to the product from its original condition.
• Use of the product for purposes other than its intended use, racing, or commercial activities, or use for purposes for which it was not designed.
• Damage resulting from failure to follow the user manual.
• Damage to paint, graphics, or decals resulting from participation in competitions, jumps, downhill riding, training for such activities, or exposure to harsh conditions or environments.
• Labor costs for replacement or modification of parts.

Except as provided by this warranty and any additional warranties, Giant, its employees, and agents shall not be liable for any loss or damage arising from or related to Giant products or their use (including loss or damage caused by negligence or fault, including incidental and consequential loss or damage).

Giant makes no other express or implied warranties. All implied warranties, including warranties of merchantability and fitness for a particular purpose, are limited to the duration of this express warranty.

Any claim under this warranty must be approved by an authorized Giant/LIV dealer or distributor. Proof of purchase or other evidence of the purchase date is required to process warranty claims. Warranty claims made outside the country of purchase may incur charges and additional restrictions. Warranty period details may vary by country. This warranty gives you specific legal rights, and you may also have other rights which may vary by location. This warranty does not affect your statutory rights.

Service Center

To find your local authorized Giant/Liv service center, please visit: www.giant-bicycles.com