Originally Posted by 96ford250
is the truck running hot? run engine and look in the degas bottle if its bubbling while the truck is running your getting compression gases into the coolant. this will push coolant out when the engine gets hot. the milky stuff on top could just be condensation from heat cycles not sure where you live but if it gets kinda chilly at night it wouldn't surprise me depending on the amount that's up there.
The motor does get hot if i run it a little hard. And it hasnt gone below 80 degrees here since ive had the truck. But if i take the oil cap off the valve cover while its running, and put my hand over it, my hand gets wet from steam. Its straight steam.