i took my boat out for the first time last night and the water pressure gauge is not working,i checked the hose and it was pumping water,so i took the hose of the back of the motor and that is pumping water fine.A buddy told me to take the gauge out and see if anything is caught inside.but i would like to know if there is supposed to be air or water in that line?i was reading on another forum that there should be air not water in the line.THANKS