21in #3 Line -4 Str/-4 Str

The 21in #3 Line -4 Str/-4 Str from ALLSTAR PERFORMANCE is a precision braided brake hose engineered for high-performance automotive applications where reliability and fluid integrity are non-negotiable. This 21-inch brake line serves enthusiasts and professional mechanics building custom fuel and brake systems—applications where OEM rubber hoses cannot withstand the demands of modified engines, aggressive braking dynamics, or remote-mounted components. Whether you're routing a brake line through a custom firewall, extending existing lines in a frame-off restoration, or installing a high-pressure fuel delivery system, this hose delivers the durability required for street, race, or dedicated track builds.

This hose features a -4 AN (1/4-inch) straight female connection on both ends, allowing seamless integration with standard AN fittings used throughout the automotive modification community. The PTFE (Teflon) inner lining resists fluid degradation and prevents corrosion from glycol-based brake fluid, while the braided stainless steel exterior provides abrasion resistance and protects against UV damage and mechanical wear. The -4 AN designation ensures 1/4-inch ID capacity, suitable for brake circuits and fuel delivery lines on engines up to moderate boost levels. At just 0.17 lbs, the hose maintains minimal weight addition—critical in competition builds where every pound matters.

This brake hose works best for builders creating custom brake systems, relocating master cylinders, installing proportioning valves, or adapting aftermarket brake bias controllers to existing platforms. The 21-inch length accommodates mid-engine conversions, remote reservoir setups, and chassis modifications where factory hose routes are no longer viable. Installation requires AN flare wrenches and basic brake line knowledge; always purge air from the system after installation and use approved DOT 3, 4, or 5.1 brake fluid. Mechanics and enthusiasts favor ALLSTAR hoses for their consistency, leak-free performance, and compatibility with professional-grade brake systems used in circle track, drag, and road racing.