What's the purpose of the radiator plastic end tank? I feel like that piece is useless. I'm running stage 2 and my first OEM radiator was leaking from that part and now my temporary one is doing the same, so now I've upgraded and bought an aluminum Koyorad Radiator, haven't installed it yet. But if anyone else having the problem too, leaking coolant from top of radiator, I suggest upgrading too. So the stock Radiator stressing from the stage 2 power and summer heat; that is my conclusion. Unless there's some internal problem I don't know about, causing too much pressure. But tell me what you think or know?