Review on 🔧 Brass Transmission Line Fitting: Derale 13031 5/16" Cooler Line to 3/8" NPT Hose Barb - Universal by Mario Beaklini

If you buy these don't use teflon tape. Use oil resistant RTV caulk, caulk, or silicone on the 3/8 threads. If you use something else they will leak a lot. My first kit came with a Derale transmission cooler. We used Teflon on two separate trucks and they were leaking at 3/8th threaded ports. I noticed that the 5/16 compression fitting is also leaking a bit. I've thought about fixing the fitting in case it comes loose while driving on the road, but haven't used it yet. Overall, the product is a good idea that doesn't work perfectly.