I just replaced the thermostat on my 2003 2500 5.7. Checked the stat before I put it in and it's okay but now I seem to be air locked and can't get it burped. No heat out of the heater. I want to pull the return line from the core but I'm not sure which one it is. Looking from the top one hose is a bit shorter and connects to a long barb seemingly so the hose doesn't rub on the crank pulley. Anyone no for sure which one it is?

 

"Burping" air from your coolant system DIY

 

Well first of all there is no rad cap on the rad itself only on the plastic overflow tank. Tried all that except letting it cool and starting over. I'll try that now and see what happens.