Guys i do not understand how the cooling system works on our cars, what is the job of the filler neck!!!! i have been told that its not supposed to be full, its only full when the engine is hot , is that correct?? can someone please write up how exactly the coolant system works on this thing and what the ast and the resevoir and filler neck do for each other please i need to understand this stupid cooling system on the car help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!

 

no cursing in the title please