Picture this: you're under the car, swapping in a new transmission cooler, and bam—mismatched line sizes staring back at you. Frustrating, right? That's where this Derale 13031 fitting steps in. It bridges a 5/16" transmission cooler line straight to a 3/8" NPT hose barb with zero drama.
Made from solid brass, this adapter laughs off corrosion, heat, and the daily grind of engine bay life. Unlike plastic fittings that crack under pressure, brass holds up to the 200+ PSI demands of most transmission systems. It's got that satisfying heft when you pick it up, and threads that bite in smooth without cross-threading if you go easy.
I've used these on everything from daily drivers to weekend tow rigs. Keeps fluid temps down, prevents overheating on long hauls, and dodges those expensive rebuilds from poor cooling.
Whether you're towing a trailer up a mountain pass or just want better efficiency from your automatic, proper line fittings matter. This one's been a staple in shops for years because it works without fuss. Pair it with high-flow coolers for max performance, or use it stock to fix a bungled previous install.
Customers rave about how it eliminated drips after old rubber hoses failed. One guy said it saved his vacation when his tranny started slipping—quick swap roadside, back on the road. If you're wrenching on Fords, Chevys, Dodges, or even some JDM rides, check your line sizes and snag this.
At under 2 ounces, it's light on the budget but heavy on duty. Keep your transmission happy and your drives worry-free.
