How to Replace the Water Pump Impeller in a Boat
The water pump impeller on a boat is a crucial piece of equipment that allows the water pump to pump water through the motor to keep it cool. The impeller is a rubber turbine that, when it turns, creates a vacuum in the pump body and draws water through the pump and the rest of the motor. Replacing the impeller is a common maintenance procedure as over time it can become cracked and worn.
Examine the bottom of the motor and find the four mounting screws holding the bottom shroud on. Use a screwdriver to remove the screws and disconnect the wiring harness inside the shroud.
Slide the lower shroud off of the motor and then clamp the lower shroud in the vice. Locate the water pump housing (shaped like a silver bell) and use the socket wrenches to remove the mounting bolts around the corners. Slide the housing up and off of the transmission shaft and the use a set of pliers to pull the impeller out of the housing.
Insert the new impeller into the housing and slide the housing back down the transmission shaft. Remount the housing with the mounting bolts and then slide the lower motor shroud back into place on the bottom of the upper motor shroud. Make sure to reattach the wiring harness and then secure the motor shroud with the mounting screws.







