i know this is an old thread but is it best to refill coolant without the thermostat in? i'm having trouble getting the system to refill....

the top port broke off the radiator and i'm tring to get by until i can afford a new radiator. there was just enough left to tighten the hose back on but its gonna worry me until i can get a new one. i got the engine up to temp and its not leaking. i slightly opened the plug on top of the thermostat housing and coolant started to leak out so i didn't open it all the way....

should i let it cool and then pull the thermostat and then run it while topping off the expansion tank?

thanks in advance!