The only maintenance that is required is what all manufacturers recommend. And that is to inspect your pump, float switch and sump basin every 4-6 months to insure that they are operating properly and there is no debris in your basin that could impede the pump or float switch operation. Oil should NOT need to be added at any time unless the pump develops a leak which is pretty rare. If that should happen, it's usually easier to have it serviced at a local authorized Zoeller service center or replace the pump.