... I hate coolant leaks. they lower the pressure in the system and that lowers the boiling point of the coolant. I had a similar situation with my V-8 Wagoneer. It turned out to be a leaking freeze plug in the back of one of the heads where only a mirror could see it. With the old vehicles that ran at cooler temperatures we could reduce the leakage by using a non-pressure cap.

... Try tightening the hose clamps, you may have to add worm-drive type clamps. If you can’t find the leak adding a small amount of dry powder type radiator sealer should work for a while.

Hope you can find and fix it.

Have a good one, and see you later.. Don S..