Radiator loosing water, engine does not run hot, the antifreeze over flow never changes from initial

The pressure bills, and it blows the top of the radiator, next time it blows the the upper radiator hose. Radiator never loses water till it blows.

 

?? Put on a new radiator cap? They do go bad.

 

Are you sure there's no air in the system? Did you properly burp the system when you refilled it? Did you fill with the heat on full blast to ensure you're getting all air out of the system, and there's nothing trapped en route to the heater core?

Have you done any maintenance that required draining/refilling fluid? How old is the radiator and how many miles on the truck, knowing the transmission lines pass thru the bottom of the radiator, which can lead to pink milkshake in the transmission?

 

I'd be checking for HC's in the cooling system. Head gasket leak chemical test.

 

Stuck thermostat?

 

Gotta be a cap issue. Even with a blown HG, etc.....pressure should always vent into the overflow first.

Get yourself an OEM cap before doing anything else and see if that fixes it.

Does it ever overheat? (on the gauge)