My stock radiator recently went out on my truck and i decided to put a 34" radiator. I know it bolts straight on but after i installed it all the coolant leaked thru the overflow hose next to the drain plug. anyone know whats wrong with the instalation.

 

Have you checked Radiator Cap?

 

No I haven't but even when I open the cap and put coolant in it leaks right away. Do u think it can be the thermostat?

 

Ya, actually I am also thinking for bad thermostat. Just do one thing touch both the upper and lower radiator hoses when the engine is warm and the car turned off. They should both be somewhat warm. If one is cold then its somewhat indication of bad Thermostat.