Went for a test drive (another 5hr idle through the woods in low range) and I could smell coolant. Stopped and popped the hood and the header tank on the rad was cracked and leaking. It was broke before and I JB welded it, well poo, have to turn around I guess. Actually, the rad hose is hard and when I moved the cap a bit, coolant came out....huh...ok, watch the temp gauge and carry on. Stopped an hour later and the rad is dry? Weird.
Then I remembered I just dumped head gasket sealer stuff in the rad before we left, I’m thinking it sealed it up?? This thing has been eating coolant for a year now, put two different types of rad sealer/head gasket sealer in it trying to stop it. (Pretty sure a head is cracked)
This time I put in cast iron block sealer... seems to work!
I’ll check coolant levels today and see if it lost much.