Both times (another story) I have replaced my radiator the bottom connection for the transmission cooler has been a source of leaks. The leak occurs where the 3/4NPT pipe screws into the transmission cooler on the radiator. This joint is further complicated by the fact that a TEE is on the other end of pipe nipple, and the TEE is where the transmission temp is taken for the gauge on the dash. You can’t just spin the nipple to make it tighter without the TEE hitting the fan shroud. And I added a