SKU: AAA1032404
MPN: A1P1032404
The 3/8-24 to #4 Steel Inverted Male Flare Adapter from A-1 Products is an essential hydraulic fitting for technicians and enthusiasts managing brake systems, fuel lines, and transmission cooler circuits. This adapter bridges two different thread standards, allowing you to connect incompatible line sizes without costly component replacement or system redesign. Whether you're building a custom fuel system for a performance engine swap, restoring a classic vehicle, or troubleshooting OEM hydraulic connections, this adapter eliminates guesswork and ensures leak-free operation under pressure.
Constructed from durable steel with an inverted male flare configuration, this fitting uses a proven 37-degree flare seat design that prevents micro-leaks at high pressures—critical in brake and fuel delivery systems where even slight seepage can compromise safety or performance. The 3/8-24 thread on one end accommodates standard -4AN hose lines (common in aftermarket and race applications), while the #4 flare end accepts traditional automotive brake or fuel tubing. A-1 Products' precision machining ensures tight tolerances and repeatable performance across multiple installations, making this adapter ideal for custom fabrication, system modifications, and emergency repairs when factory-spec fittings aren't available.
This adapter benefits experienced mechanics, hydraulic system builders, and weekend warriors upgrading fuel or brake systems on street rods, race cars, and modified trucks. It's particularly valuable during engine transplants where donor and receiver vehicles use different hydraulic standards, or when converting to braided stainless steel lines for improved durability. Installation requires basic wrench skills and a flare-nut wrench to prevent line damage; always apply thread sealant rated for fuel or hydraulic fluid, and torque connections to manufacturer specs. Verify thread pitch and flare diameter compatibility with your existing components before ordering to avoid fitment issues.
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