I have a 646 1975. I replaced oil pump about ten hours use ago. Got all my power back. I was pushing some brush and suddenly no power to move forward or backward. Loader goes up lethargically. This morning went out to see if it would move and it does very slowly almost to the point of not at all. I was sure it was the pump that went bad, so stupidly I replaced it and nothing different. I have searched a bunch of forums etc... but can not find any material that has helped. Any help is greatly appreciated.