Twist-Lok Hose #4 Black 15ft

The Twist-Lok Hose #4 Black 15ft by RUSSELL is a professional-grade hydraulic hose assembly built for serious engine builders, fuel system modifications, and high-performance cooling applications. Whether you're upgrading your vehicle's fuel delivery system, installing a custom cooling loop, or running a turbo charging system that demands reliable pressure containment, this hose delivers the durability and consistency that experienced mechanics depend on. Twist-Lok fittings have earned their reputation in the automotive aftermarket for leak-free connections under demanding conditions.

The size #4 designation refers to a 1/4-inch inner diameter, making this hose ideal for fuel lines, coolant circulation, and brake fluid applications in modified vehicles where standard OEM hoses cannot handle the pressure spikes or temperature extremes. RUSSELL's Twist-Lok design eliminates the need for clamps at the connection point—the fitting itself seals via a mechanical twist-lock mechanism, reducing vibration-induced loosening that plagues traditional hose setups. The 15-foot length provides flexibility in routing around engine bays, through firewalls, and along chassis during complex plumbing scenarios. The robust black outer cover resists oil degradation, UV exposure, and abrasion from engine bay heat and movement.

This hose is favored by transmission cooler installations, fuel system upgrades on forced-induction engines, and custom water cooling builds where pressure reliability is non-negotiable. Mechanics and fabricators rely on Twist-Lok hose for its ability to maintain seal integrity across thousands of heat cycles and pressure fluctuations without weeping or separation at the fitting. Installation requires no special tools beyond a wrench for the connection point—simply match your fittings' thread size and insert into the Twist-Lok end until hand-tight, then rotate slightly for final engagement. Verify compatibility with your specific fittings and system pressure rating before installation.