Shallow well jet pumps circulate water from well systems a small distance below the ground. A jet pump uses centrifugal force and an injector-like system to move water through plumbing pipes. A motor powered shaft spins at high speeds, rotating an impeller that creates the centrifugal force used for water movement. Repairing a shallow well jet pump involves troubleshooting the pump's spinning impeller and replacing the seal on the shaft used to protect the motor from leaks.
Disconnect the jet pump from the surrounding plumbing. Unfasten the bolts on the larger circular middle housing of the jet pump using a wrench. Pull apart the housing to reveal the impeller, volute or impeller covering (if one exists) and shaft.
Pull the volute off the impeller. Unscrew the screws holding the volute to the pump casing with a screwdriver. Fasten a wrench around the section of the shaft behind the impeller. Hold the wrench still and twist the impeller counterclockwise to disconnect it from the shaft.
Pull the small pump seal off the shaft. Do not strip the threads on the shaft by forcing the seal too roughly over the shaft. Slide a new seal down the length of the shaft until it rests against the back of the shaft.
Fasten the wrench around the shaft in front of the seal and slide a new impeller on the shaft up to the threads. Turn the impeller clockwise until it is fully threaded. Place the volute on the impeller and fasten it into place with screws and a screwdriver if needed.
Place the two sections of the pump housing together with the bolt holes lining up. Insert the bolts and tighten them with a wrench. Reconnect the shallow well jet pump to the existing plumbing.