I have an 1838, and also a dumb question. On the fuel filter it has a valve to release the water from the fuel. first of all, where does the water come from? and second, do I leave the valve open until nothing comes out? I dont want to have to bleed my fuel system again (that wasnt any fun), or do I just let it run until I know it is straight diesel coming out? I looked in my service book, but apparently you are just supposed to know what to do with it. Thanks-chris