21in #4 Line -4 Str/-4 Str 5pk

The 21in #4 Line -4 Str/-4 Str 5pk from ALLSTAR PERFORMANCE is a professional-grade brake hose assembly designed for custom hydraulic brake system builds, high-performance racing applications, and engine bay modifications where factory hose routing cannot accommodate performance requirements. This five-pack set delivers the critical infrastructure needed to plumb custom master cylinders, proportioning valves, and caliper combinations with precision and reliability. Whether you're upgrading to dual master cylinders, relocating brake components for weight reduction, or fabricating a dedicated circuit for track use, these hoses provide the correct fitment for seamless integration into your brake system architecture.

Each 21-inch hose features a 4 AN straight female connector on both ends, enabling direct coupling to 4 AN male fittings on master cylinders, proportion blocks, splitters, and caliper inlet ports without adapter complications. The hose interior is PTFE (polytetrafluoroethylene) lined, a synthetic polymer that resists corrosion, maintains chemical stability across brake fluid types, and prevents internal degradation over extended storage or high-temperature cycling. The braided stainless-steel exterior layer provides mechanical protection against abrasion, vibration damage, and engine bay heat while maintaining flexibility for tight-radius bends and complex routing paths. This construction standard is the industry baseline for serious brake system work and meets SAE J30R7 specifications for reliability under sustained pressure and thermal cycling.

This five-pack is ideal for builders constructing dual-circuit brake systems, remote brake bias adjusters, or multi-caliper circuits where individual hose lengths and symmetrical routing reduce pressure lag and improve pedal feel consistency. The 21-inch length accommodates mid-engine conversions, rear-mounted master cylinders, and lateral component spacing common in custom fabrication work. Mechanics and fabricators benefit from the bulk quantity, as it reduces inventory gaps during iterative system testing or provides spares for field repairs at the track. Verify all 4 AN fittings on your brake system architecture before ordering to ensure compatibility; this assembly is non-returnable once cut or fitted.