RCB E2 MASTER BRAKE HYDRAULIC CLUTCH 14MM LEFT HAND – BLACK

RCB E2 Series Left-Hand Master Cylinder (14mm) is a versatile, high-performance hydraulic control unit engineered to optimize leverage and pressure. Finished in a sleek, stealthy matte black, this assembly serves as an excellent upgrade for motorcycles utilizing a hydraulic clutch system, or as the main rear brake master cylinder on maxi-scooters with dual handlebar levers.

Featuring a balanced 14mm internal bore piston, the E2 series strikes the perfect technical compromise: it decreases the physical effort required at the handlebar lever while dramatically increasing linear fluid displacement for a highly communicative, responsive feel.

Key Features

• Optimized 14mm Pressure Bore: The precision-ground 14mm internal piston provides exceptional fluid modulation. It reduces the mechanical stiffness of heavy-duty manual clutch springs or multi-piston rear brake calipers without introducing a spongy lever response.

• Ergonomically Sculpted Alloy Lever: Features a high-strength aluminum lever arm contoured to fit comfortably against your fingers. Its specific curvature maximizes leverage efficiency, reducing hand fatigue during tight technical trail riding or heavy stop-and-go city traffic.

• Integrated Tinted Fluid Reservoir: Outfitted with a compact, smoky transparent fluid reservoir tank mounted directly to the master cylinder body. This design allows you to visually inspect brake fluid levels and degradation quality at a quick glance without opening the reservoir cap.

• Safety Foldable/Flex Lever Architecture: Engineered with an anti-snapping pivot point. In the event of a low-side slide or tip-over, the lever arm is designed to flex upward rather than snapping off completely, ensuring you aren’t left stranded without a clutch or brake control.

• Built-In Brake Light / Safety Switch: Includes a pre-wired mechanical micro-switch assembly that integrates smoothly into your motorcycle’s factory wiring loop to trigger rear brake lights or function as a clutch safety starter interlock.

Technical Specifications

Dual Application Versatility

• As a Hydraulic Clutch Master: If you are converting a heavy, stiff cable clutch system over to a hydraulic secondary slave cylinder, this 14mm master cylinder provides the exact hydraulic ratio required to pull the clutch pressure plate smoothly, resulting in a feather-light lever feel.

• As a Rear Scooter Brake: For maxi-scooters like the Yamaha NMAX or Aerox converted to rear disc brakes, the 14mm piston pushes enough fluid to trigger single or dual-piston rear calipers instantly, offering sharp, progressive trail-braking control.

Installation Guidelines

1. Protect Your Fairings: Brake fluid acts as a harsh solvent and will quickly dissolve painted fairings or instrument lenses. Always drape a heavy protective towel or plastic sheet over your fuel tank and handlebars before opening the fluid circuit.

2. Verify Banjo Bolt Threading: The E2 series utilizes an M10 x 1.25mm thread pitch banjo bolt inlet. If your motorcycle’s factory line utilizes an M10 x 1.0mm pitch, using the old bolt will permanently strip the aluminum threads inside your new master cylinder. Always use the fresh copper crush washers included in the kit.

3. Bleed the Master Cylinder First: Air bubbles love to trap themselves directly inside the highest point of the hydraulic loop—the master cylinder piston cavity itself. Before attempting to bleed from the slave cylinder or brake caliper below, pump the lever slowly and crack the banjo bolt slightly to purge the air trapped at the top of the system.

4. Set Lever Angle for Reservoir Levels: Position the master cylinder clamp on your handlebars so that the fluid reservoir sits as level to the horizon as possible when the front wheel is straight. This prevents the internal intake port from accidentally sucking in air when the fluid level drops slightly over time.