#12 O-Ring to 1-3/4in Hose - Black

The #12 O-Ring to 1-3/4in Hose - Black fitting from Meziere is a precision water pump connector designed for high-performance cooling system integration. This straight adapter joins AN (Army-Navy) -12 male ports with O-ring face seals to 1-3/4-inch barbed hose connections, making it essential for custom cooling loops in racing engines, street performance builds, and aftermarket water pump installations. The adapter bridges the gap between modern quick-disconnect fittings and traditional hose barb configurations, ensuring reliable coolant flow without leaks under pressure.

Constructed from aircraft-grade aluminum with black anodized finish, this Meziere fitting resists corrosion while maintaining a professional appearance in engine bays. The O-ring seal design provides superior leak prevention compared to tapered thread fittings, eliminating the need for thread sealant and reducing installation time. The straight configuration minimizes flow turbulence and pressure drop, critical for maintaining optimal coolant velocity in performance applications. The 1-3/4-inch hose barb accepts standard aftermarket cooling hoses with a secure, compression-style connection that tightens as internal pressure increases.

This fitting serves enthusiasts upgrading factory cooling systems, fabricators assembling custom water pump kits, and engine builders integrating modern circulating pump designs into vintage platforms. Compatibility extends to any cooling system using #12 AN (standard for mid-range flow applications) inlet/outlet ports paired with 1-3/4-inch silicone or rubber hose. Installation requires hand-tightening the O-ring connection until snug, then application of modest wrench pressure—over-tightening damages the seal. Verify O-ring condition before assembly and use compatible coolant to prevent degradation of sealing surfaces.