I know it's is going to sound ignorant but I have 2 questions. First is the radiatior cap the large cap on the overflow bottle. Also I added antifreeze the other day because the low coolant light went on. There a small leak that's yet unfound and I know about the common leak area on the overflow tank but when I added a little antifreeze to get the light off I not sure if I closed the cap all the way where you hear the clicks. My wife took a small ride and when she got back there was antifreeze steaming off the engine I looked but couldn't see any leaks but I also noticed a bubbling sound coming from cap. Would be not closing the cap tight have caused it to overflow from the cap or other spots. Tia

 

Yes, they used to be on the radiator and now often get called by the old name.

If loose or cross-threaded you'd get a leak and as it's meant to be a pressurised system it'll make a mess. Top up when cold but you do need to find the leak as well.

BTW the really silly questions are those not asked that need to be! We all start off ignorant when born....