Why does a closed loop radiator need hot coolant?
Why does a closed loop radiator need hot coolant? Heated coolant also expands so a closed loop system will require coolant to be held in rather than boiled out. A closed loop system will also need an overflow tank which is reclaimed upon cooling of the system. A functioning radiator cap will maintain its rated pressure. Can a defective radiator cap cause engine to overheat? A defective radiator cap will cause engine overheating in a number of ways. Three of the ways a radiator cap can cause overheating are, 1) Not holding in pressure and allowing the coolant to vent...