Tube Adapter

The Wilwood tube adapter (SKU WIL220-0628) is a precision brass fitting engineered for high-performance brake system modifications and custom hydraulic line routing. Whether you're building a custom braking setup, upgrading to a higher-capacity master cylinder, or adapting legacy hardline configurations to modern proportioning valves, this adapter delivers the reliable connection mechanics depend on. Available as a set of four, these fittings eliminate the need for costly custom hardline fabrication and reduce installation time on track cars, restorations, and performance street vehicles.

Each tube adapter features a 3/8-24 inverted flare female thread on one end and a 1/8 NPT male thread on the opposite end, making it ideal for transitioning between 3/16-inch hardline brake tubing and NPT-threaded proportioning blocks or residual pressure valves. Constructed from durable brass, the fitting resists corrosion and maintains structural integrity under repeated pressure cycling—critical for brake systems operating at 800+ PSI. The inverted flare design creates a positive mechanical seal without requiring secondary sealing compounds, ensuring leak-free performance and simplifying future service or adjustment.

Professional mechanics and enthusiasts favor Wilwood adapters for OEM brake system replacements, dual-reservoir builds, and master cylinder relocations where standard off-the-shelf hardlines won't fit. The set of four adapters accommodates typical four-wheel brake circuits, front/rear splits, or spare inventory for future upgrades. Installation requires only standard wrenches and basic hardline flaring knowledge; compatibility extends across most domestic and import platforms using SAE flare brake standards.