RCB E3 PLUS (E3+) MASTER BRAKE HYDRAULIC CLUTCH 14MM LEFT HAND

RCB E3 Plus (E3+) Left-Hand Master Cylinder (14mm) represents a highly refined milestone in RCB’s performance control lineups. It brings enhanced structural casting, sleek styling, and precision hydraulic actuation directly to your handlebars.

Engineered with a versatile 14mm internal bore piston, this premium hydraulic control unit acts as a high-efficiency hydraulic clutch master cylinder on manual motorcycles or as a highly communicative, responsive rear brake master cylinder on disc-brake equipped maxi-scooters. The E3 Plus designation stands out for its high-clearance design, delivering precise lever reach adjustment and exceptional fluid modulation right at your fingertips.

Key Features

• Premium Dial-Adjustable Lever Reach: Built with an indexed external adjustment wheel dial. By turning the dial clicker, you can easily alter the resting position of the lever blade closer to or further away from the handlebar grip, allowing for tailored ergonomics that match your hand size or glove thickness perfectly.

• Highly Responsive 14mm Pressure Bore: The 14mm precision-ground internal piston provides an optimized hydraulic ratio. It moves a sufficient volume of fluid to effortlessly drive aftermarket single, dual, or small four-piston brake calipers, and reduces heavy manual clutch pulling force by up to 30%.

• Low-Profile Cast Fluid Reservoir: Features a modern, sleek fluid reservoir reservoir cast directly into the main cylinder body shell. This compact architecture provides excellent structural clearance against mirrors, windscreens, and handguards when swinging the handlebars lock-to-lock.

• Integrated Level Sight Glass Window: Equipped with a crystal-clear observation window on the reservoir front face. This allows you to visually audit your brake fluid level capacity and degradation quality instantly without tools.

• High-Elasticity Folding Hinge Blade: Engineered with a robust mechanical pivot point. In the event of a low-side drop, accidental garage tip-over, or tight lane-filtering impact, the lever folds safely upward rather than shearing off completely, allowing you to stay on the road.

• Pre-Wired Micro-Switch Assembly: Includes a built-in safety micro-switch that seamlessly splices into your vehicle’s factory wiring harness to serve as a rear brake light activator or a clutch-in starter interlock mechanism.

Technical Specifications

Dual-System Performance

• As a Hydraulic Clutch Master: When replacing a stiff, binding mechanical steel clutch cable with a hydraulic slave cylinder conversion, the 14mm internal bore creates a smooth, linear friction zone. Finding neutral becomes effortless, and hand fatigue is virtually eliminated during heavy stop-and-go city commuting.

• As a Scooter Rear Disc Brake Master: For modern high-displacement scooters upshifting their rear braking performance, this master cylinder provides sharp initial brake bite combined with precise pressure feedback, allowing you to trail-brake deep into corners with total confidence.

Installation Guidelines

1. Drape Protective Shrouds: Brake fluid behaves as a highly destructive solvent on paint and plastic. Before unsealing your hydraulic line or opening the reservoir cap, completely cover your front fairings, dashboard gauges, and fuel tank in heavy protective towels.

2. Verify Banjo Bolt Threading: The E3 Plus fluid inlet is strictly threaded for an M10 x 1.25mm pitch banjo bolt. Utilizing an incorrect thread pitch bolt (such as an OEM M10 x 1.0mm) will cross-thread and permanently strip out the aluminum master cylinder housing. Always assemble using the clean copper crush washers included in the kit.

3. Perform a Master Cylinder Bench Bleed: Air bubbles naturally rise to the highest point of a hydraulic loop, often trapping themselves directly within the master cylinder chamber itself. Before trying to bleed fluid from the caliper or slave cylinder down below, pump the lever slowly and crack open the top banjo bolt slightly to purge any trapped air pockets first.

4. Set Symmetrical Horizontal Levels: Fasten the master cylinder clamp onto your standard 22mm handlebars at an angle that keeps the fluid reservoir box as parallel to the horizon as possible when the scooter is facing completely straight, ensuring the internal feed port never runs dry.