Welcome to the forum Jim. How many hours on your L355? You will soon learn it is a lot easier than you might think and Kubota makes some good tractors.
Welcome to the forum from Alabama. A couple of things, 1) While the tractor is running, can you see oil in the window? 2) If it is not pure white like a sheet of paper, it is probably too full and all you are seeing is the fluid in the window.