Does anyone know how to separate the pump housing from the motor. I have a Polaris PB-4 pump on a 3/4 hp Magnetek motor. I removed the 4 bolts holding it on but the rest isn't coming free and I don't want to break it. I called polaris and was told it is a keyed shaft and that it should slip off. Ther is signs of corrosion so I'm thinking it is just stuck.