Rekluse Foot Brake Master Cylinder Kit for KTM, Husqvarna, GasGas, Ducati and Triumph Dualsports

The Rekluse Foot Brake Master Cylinder Kit (RMS-5310006) is a precision-engineered, billet aluminum rear brake master cylinder designed to replace factory cast master cylinders on KTM, Husqvarna, and GASGAS off-road and motocross motorcycles. Factory cast units (Brembo and Braktec) are prone to fluid overheating, piston seal wear under abrasive roost, and internal port blockage that leads to lever fade and inconsistent rear wheel lockup during aggressive descent braking.

CNC-machined in Boise, Idaho from aircraft-grade billet aluminum and finished in durable hard anodizing, the Rekluse foot master cylinder features an optimized hydraulic bore geometry and high-durability internal seals that resist heat-induced pressure drop. Engineered as a heavy-duty standalone performance upgrade, it also serves as the dedicated hydraulic junction required for riders integrating a Rekluse Left-Hand Rear Brake (LHRB) system—allowing simultaneous, independent actuation from either the left handlebar lever or the standard right foot pedal. The assembly is fully rebuildable and integrates seamlessly into the OEM frame mounting tabs and foot pedal linkage.

Features:

• Billet CNC Aluminum Construction: Replaces fragile OEM cast bodies with a high-strength, hard-anodized billet housing that resists impacts and thermal warping.

• Consistent Brake Modulation: Optimized internal piston and valving provide linear pressure ramp-up, eliminating spongy pedal feel and heat-induced fade.

• LHRB Dual-Actuation Ready: Configured to operate either as a standalone high-performance foot master cylinder or as the foundational link for Rekluse dual-actuated Left-Hand Rear Brake kits.

• Durable Internal Seal Package: Long-life sealing materials withstand extreme temperature swings and high duty-cycles in muddy or sandy environments.

• Integrated Fluid Bleed Port: Engineered for simplified bleeding and flushing without trapping air micro-bubbles in internal galleys.

• Fully Rebuildable Design: Designed for long-term serviceability using available Rekluse factory piston and seal rebuild kits.

• Made in the USA: Engineered, machined, and assembled at Rekluse headquarters in Boise, Idaho.

What's in the Box:

• 1x Rekluse Billet Foot Master Cylinder Assembly (Hard-Anodized)

• 1x Master Cylinder Pushrod & Clevis Assembly

• 1x High-Pressure Hydraulic Banjo Bolt & Copper Crush Washer Pack

• 1x Frame Mounting Hardware Kit

• 1x Installation Guide & Setup Schematic

Fitment:

• 2014–2027 – KTM Enduro, Dualsport & Motocross Models

• 2014–2027 – Husqvarna Enduro, Dualsport & Motocross Models

• 2021–2027 – GasGas Enduro, Dualsport & Motocross Models

• 2026–2027 – Ducati Desmo Enduro, Dualsport & Motocross Models

• 2024–2027 – Stark Varg models equipped with rear foot brake pedal

Fitment Notes:

• Brake Fluid Type: Fully compatible with standard glycol-based fluids:DOT 3, DOT 4, and DOT 5.1.

• CRITICAL FLUID RESTRICTION: DoNOT use silicone-based DOT 5 fluid or mineral oil. Using improper fluids will swell and destroy the internal EPDM elastomer seals within minutes, causing complete hydraulic failure.

• Mandatory Pushrod Free Play (Preventing Brake Lockup): When mounting the master cylinder pushrod to the rear brake pedal clevis, you must ensure 1.0 mm to 2.0 mm of free play between the pushrod tip and the internal master cylinder piston before resistance is felt. If the pushrod is adjusted too tightly (zero free play), the internal compensating/return port remains blocked. As brake fluid heats up from rotor friction during riding, thermal expansion cannot bleed back into the reservoir, causing the rear brake to self-pressurize and violently lock the rear wheel mid-ride.

• Back-Bleeding Procedure: To achieve a rock-solid pedal without trapped micro-bubbles, back-bleed the system from the rear caliper bleeder upward through the Rekluse master cylinder using a fluid-filled syringe and clear vinyl tubing. Push fluid slowly into the caliper bleeder until clean, bubble-free fluid fills the master cylinder bleed port and reservoir. Once purged from below, close the caliper bleeder, top off the master cylinder port, and reinstall the bleed screw.

• Plastic Frame Guard Clearance: Depending on the year and brand of your motorcycle's aftermarket or OEM plastic frame guards (particularly on newer KTM/Husqvarna SX-F and XC-F generation frames), verify clearance around the upper body of the billet master cylinder. The precision CNC-machined body has marginally squarer shoulders than the tapered stock cast body; if the guard contacts the cylinder or banjo fitting, notch the plastic guard slightly with a rotary tool or razor knife to ensure stress-free alignment.

Part Number: RMS-5310006