5/16in Radiator Transmis sion Cooler Plug

The 5/16in Radiator Transmission Cooler Plug by Cold Case Radiators is an essential component for custom cooling system builds and transmission cooler retrofits. This precision plug seals transmission cooler line ports on radiators when upgrading or customizing your vehicle's thermal management system. Whether you're building a high-performance street rod, upgrading a classic muscle car, or installing an aftermarket transmission cooler on a modern platform, this adapter fitting ensures clean, leak-free connections while maintaining system integrity under pressure.

Engineered to Cold Case Radiators' exacting standards, the 5/16-inch plug accommodates standard transmission cooler hose sizes found on most domestic and imported vehicles. The compact profile (2.5 x 0.65 x 4.65 inches) allows for tight installation spaces common in engine bays, while the minimal weight (0.02 lbs) eliminates any performance penalty. This fitting is manufactured to prevent fluid weeping and maintain system pressure across a wide range of engine operating temperatures, critical for protecting your transmission fluid and extending cooler life during demanding driving conditions.

Mechanics and fabricators rely on Cold Case Radiators plugs when deactivating stock transmission cooler ports or transitioning between different cooling configurations. This fitting works with any radiator featuring 5/16-inch threaded or barbed ports, making it ideal for custom cooling loops, engine swaps, and performance cooling upgrades. Installation is straightforward—apply appropriate thread sealant and torque carefully to avoid damaging the aluminum radiator ports. Stock this plug when planning transmission cooler modifications, ensuring you have the proper fittings on hand before breaking down your cooling system.