RCB E2 SERIES BRAKING SYSTEM
RCB S1 SERIES BRAKING SYSTEM
Recommended Additional Upgrades
01
S1 FL 30th Anniversary Special Edition
Get the Combo set for the ultimate brake system upgrade.
RCB S1 Alloy Brake Fluid Tank Cap is a premium CNC-machined replacement for the standard plastic reservoir caps found on S1/S1-FL Master Brake Pumps. As part of the S1 Series, it is designed for riders who prioritize high-end finishing and durability.
Beyond the aesthetic upgrade, this cap provides a more rigid seal for the brake master cylinder, ensuring the hydraulic system remains pressurized and free from moisture contamination.
Key Features
CNC Machined Billet Aluminum: Carved from a solid block of high-grade aluminum, offering significantly more strength and heat resistance than factory plastic caps that can warp or crack over time.
Leak-Proof Precision: Designed to fit perfectly with the original rubber diaphragm (gasket). The precision threading ensures a tight seal, preventing corrosive brake fluid from leaking onto your paintwork or fairings.
Deep Anodized Coloring: Features a high-gloss, UV-resistant anodized finish. Unlike painted parts, this color is chemically bonded to the metal, ensuring it won’t peel or fade even when exposed to harsh brake fluid or direct sunlight.
S1 Signature Styling: The cap features the iconic RCB S1 geometric patterns and branding, providing a sophisticated “cockpit” view for the rider.
Technical Specifications
| Feature | RCB S1 Tank Cap Details |
| Material | T6 Billet Aluminum Alloy |
| Series | S1 (Performance & Styling) |
| Finish | Anodized (Red, Gold, Blue, Black, Silver) |
| Compatibility | Universal Round 15ml Fluid Tank |
| Installation | Direct Screw-on Replacement |
Why Upgrade to the RCB S1 Cap?
Chemical Resistance: Brake fluid (DOT 3, 4, or 5.1) is highly corrosive. Plastic caps can eventually become “chalky” or brittle due to chemical exposure. The T6 alloy remains unaffected.
Visual Consistency: If you have already installed RCB S1 Master Cylinders or Clutch Levers, this cap completes the uniform look of your handlebar controls.
Durability: In the event of a minor tip-over or impact, a plastic cap is prone to shattering, which can disable your brakes by letting air into the system. An alloy cap provides a much higher level of protection.
Installation Guidelines
When swapping the cap, use a clean cloth to wipe away any excess brake fluid from the rim of the reservoir before installing the new cap. Ensure the internal rubber diaphragm is seated flat; if the diaphragm is twisted, the system will not seal correctly, leading to “spongy” brake feel.
