Recently replaced a failed water pump, and put in a new thermostat. Flushed & filled the cooling system. Everything went well until I towed a 1500 trailer down the interstate @ 80mph. 25 miles from home I notice the temp rise quickly, so I kill the AC. Temp doesn't drop, so I pull off to investigate. Temp is holding at around 245° with the E-fan constantly running. I let it sit & cool for a bit, then check coolant. I find a muddy rusty nasty mess in the radiator. [emoji2959][emoji2959][emoji2959][emoji2959][emoji2959] I hooked the trailer to my wife's JKU, and back down there road I go. Temp holds at about 225°. We made it through family lake day, but just barely. Now I gotta flush it again.[emoji2959] Anyone know a good coolant additive for rust prevention? One that's not snake oil! The curious thing is that I have 2 TJ's, and a YJ. None of them have this issue, and I fill them with the same coolant & water.