Last month I replaced my head gasket, water pump and thermostat and its all good but I noticed sometimes it leaks coolant out of the holding tank. I dont remember if I put it in backwards, I live in Michigan and last month we had some sub 0 temps when I was doing the HG job, my brain was frozen Wouldn't it overheat if the coolant wasn't traveling arround the engine? It's been a month since I've replace the thermostat so wouldn't something happened by now? Maybe could it be the radiator cap? <<<(the one thats not really on the radiator) I'm puzzled, so thanks for all your help guys.