Hyundai Repair: Overheating, coolant tank, coolant level

Question
The overflow cap to my radiator was broken and I am waiting for a replacement from the dealer.  My question is, if the overflow cap is broken and cannot circulate to the radiator when it needs to, would this cause overheating of the engine?

Answer
Hello Dianna,
No it will not cause an overheating directly. It is an extra coolant tank for the system. When it is hot and coolant level rises it holds that extra collant for system to reuse when needed. If your engine has no coolant leak and no former overheating problem, I think you can wait until the part arrives.