Rebuild kit for plastic body seawater pumps on Bravo drives For 50 years Sierra has been producing parts engineered to meet or exceed the specifications of marine engine manufacturers and has gained the confidence of engine manufacturers and boat builders to the point of supplying them with OEM parts. Boaters and technicians can be assured a Sierra part will fit right the first time and restore function to OEM specifications. Sierra water pump kits include all you will need to rebuild a seawater pump. An impeller, a wear plate, the required O-rings, and associated fasteners make the task of rebuilding the water pump straightforward. We recommend having a spare impeller (Sierra part no. 18-3087) onboard to be prepared in the event of an unexpected failure due to debris or system blockage.