20999384
Elbow Nipple
Mack

An elbow nipple is a compact 90-degree fitting used to route air or fluid lines in tight engine bays and brake circuits. This part provides a reliable, airtight connection between hoses or tubes with standard thread or compression fittings, enabling smooth directional changes without kinking. In Mack applications, it helps route lines around headers, starter motors, or frame rails, preserving flow and reducing stress on hoses. Constructed from steel, brass, or corrosion-resistant alloys, it resists vibration and thermal cycling. The smooth internal bore minimizes turbulence and pressure drop, supporting steady performance across manifold pressure ranges. Proper engagement of threads and seals prevents leaks at high system pressures, and correct installation torque reduces the chance of thread galling. This elbow nipple is a precision-fit component; selecting the correct size and thread type is essential to maintain system integrity, prevent leaks, and avoid pressure loss that can impair braking or pneumatic operation. Regular inspection for wear, cracks, or corrosion helps prevent unexpected failure in the field. When replacing, ensure compatibility with the existing line connectors and follow manufacturer's installation guidelines. Source One Parts Center, your Mack parts partner.