2007 E450 V10 with 100000 miles.
About 2 years ago I started consistently loosing a small amount of coolant. Averaging about a pint a week. I spent over an hour a few times crawling around with a flashlight to no avail. The entire engine bay was immaculate and looked brand new. After researching online I found several posts here and other forums about the reliability of Fords push on hose clamps and several recommendations that the clamps should be replaced around 60000 miles. After knowing where to look I did find a tiny amount of corrosion around two of the small lower radiator hose clamps. I bought new Gates hoses and new worm drive clamps but before I hade time to replace the lower radiator hose I sold the truck. I gave the new owner the hose and clamps and told him to have it installed to stop the coolant loss. He never did it. He had a mechanic replace what I believe to be a perfectly good radiator and he is still experiencing coolant loss. This same mechanic told him the hoses are not leaking. I’m 99% certain that he is wrong. Two years ago I found a few threads here about this saying it was a known issue but now I can not find any mention of this problem. Can anyone show me a few links to these posts?
Thank you for reading through this long post

 

The Ford constant tension clamps are very reliable and offer better protection during changes in operating temperature. If there was a leak due to a weak clamp you'd know it.

I would test for combustion gasses in the cooking system.

-- Dave