I have a Neptune Mighty Mite model 11a1 . It is up and running well now . I need to know how to confirm that the water pump is working. My understanding is that these small motors need to have the return line from the head to the gear case in place and sealed for the pump to work , that the gravity on the return line helps the pump work [ no real head pressure needed] That line exits very near the prop and underwater so there is no visual way to see if its pumping. Any ideas would be welcome