#10 O-Ring #12 Flare Adapter Black

The #10 O-Ring #12 Flare Adapter Black from AEROQUIP is a critical hydraulic and fuel system coupling component designed for high-pressure fluid transfer in performance automotive and motorsport applications. This adapter bridges two different port configurations—a #10 O-ring boss connection and a #12 flare port—allowing technicians to integrate incompatible line fittings without compromising system integrity. Whether you're building a custom fuel system, upgrading brake hydraulics, or assembling a race engine's cooling or lubrication circuit, this adapter eliminates costly rework and ensures proper flow path continuity.

Manufactured by AEROQUIP, a trusted OEM and aftermarket supplier for aircraft and automotive fluid systems, this adapter features a black-anodized aluminum or steel construction that resists corrosion and maintains structural rigidity under pressure cycling. The O-ring sealing surface on the #10 end creates a metal-to-elastomer seal rated for high-pressure service, while the #12 JIC (Joint Industry Council) flare connection on the opposite end accommodates standard 37-degree flare fittings used throughout domestic and import performance platforms. The compact 3.55 x 1.7 x 5.35-inch footprint and minimal 0.12-pound weight make it ideal for tight engine bay packaging on street rods, turbo kits, fuel-injected conversions, and race car builds where space and weight discipline are paramount.

Professional mechanics, engine builders, and DIY enthusiasts upgrading fuel delivery, cooling systems, or brake circuits benefit most from this adapter when retrofitting modern fuel injectors, aftermarket fuel rails, or upgraded cooling components onto vehicles with legacy or mixed-port manifolds. Installation is straightforward: torque the O-ring end hand-tight plus a quarter-turn to avoid over-compression, then secure the flare end with the appropriate wrench on both nut and body to prevent line twisting. Verify port sizes on both existing hose assemblies before ordering; this adapter is non-returnable once opened, so confirm MPN FCM5954 matches your specific O-ring and flare configurations for leak-free, long-lasting performance.