A few things to remember on these units. One is as long as the pump is supplied with oil, they last almost forever. Also, that oil has to be clean oil. Next the power coupling from the engine to the pump must be tight. If you had low or no oil going into the pump due to a slipped coupling, you could begin to seize the pump. Fix the coupling and ensure oil is flowing through the pump and that it is clean. If no power I would suspect the pump.