im losing coolant out my overflow tube. i replaced the cap but im still getting a leak I cant seem to figure out what the problem is and the coolant is not over filled.

 

Sounds like pressure is building up somewhere.

 

Is the overflow bottle full? Because like dodge dude had said, you maybe building up pressure in the radiator and the coolant is over flowing into the bottle.

 

the overflow bottle is about a quarter down from the full line.even when its filled it leaks the truck has a new radiator.what should I check next?

 

I would perform a cooling system pressure test.

 

did the pressure test today was normal now what should i check?

 

The nozzle that the rubber overflow tube connects to could have a crack where it meets the filler neck of the radiator. Or could just be a loose fit. Or the hose itself could have a hole. I would replace the hose next, and maybe put a small clamp on it.

 

Blown headgasket or cracked head could cause the same problem. I would think it would show on a pressure test though...