Water in oil

We have a JD 410C I was getting water in the oil. I replaced all o rings and gaskets in the oil cooler. Ran engine for an hour and no water in the oil. After 2 hours of digging I check the engine oil again, and there is water in the oil. I did a pressure test on the cooling system without the radiator included, and the engine held pressure at 20 pounds for 6 hours. How else can water be getting into my engine? It did just raIn for 4 straIght days, could water be entering the engine from rain? I know if anything's possible and I know this can happen, but does anyone have any other suggestions? ActuAlly this is A continuAtion of Another threAd called wAter in oil, but my phone didn't seem to be adding it correctly to the thread. Thanks