I have a flotec sprinkler pump that lost its prime. I have troube-shot everything. The pipe that draws the water in from the canal is not cracked. The pressure valve at te end of that pipe works fine. I have narrowed the problem down to the pump itself. I opened it up, the seals are fine, the impeller spins when turned on. I cleaned the seals and put it back together, I pressurized the system and no water leakes from the pump, but when I turn it on, it only pushes a miniscuel amount of water to the sprinkler heads and barley has a suction. I am lost, any suggestions?

Garden - Flotec - 1 - 1/2 Sprinkler Pump Composite Quick Priming High -...