I am new here. This is a great site. I have an R33 GTR Vspec. I replaced my cracked stock rad and fan with a Mishomoto rad and fan shroud. The car did not overheat with the stock rad but did with the Mishimoto. We tried cutting out the fan shroud so that the aircon fan could blow through the rad but the car would still overheat even at idle on a 25 deg day. We switched back to a factory fan and overheating is gone. But now I notice coolant on the top of the rad and it seems to be pushing through the Mishimoto rad cap on hot days. Looking at the setup I can't see how the coolant overflow bottle can work, as the overflow hole is above the point where the cap seals, see below photo. So it seems like the coolant is heating up, expanding and then has nowhere to go except past the cap seal. You can see the red coolant on the top of the rad. I can't remember if the setup is the same on the stock rad. Can someone with a stock rad check for me? I also noticed that the coolant was boiling in the hoses today, which was 30+ deg. Is this normal? Any advice is appreciated.