I was spraying away and all of a sudden the pressure dropped and started dribbling!! I was gettin down towards the bottom of the tank, but not completely empty. So I went back and refilled and went back out and I couldnt get the sprayer to prime. ANY IDEAS??? I took off 2 of the 3 diaphrams and replaced them and checked the o rings, but still no luck. Maybe its the diaphram next to electric motor. It is a hypro D403 pump. THanks Could it be the valves??