Johnson Pump 09-1028B-9 F7B Impeller (Nitrile)

The Johnson Pump 09-1028B-9 F7B Impeller in Nitrile is an essential replacement component for marine cooling systems, particularly those running F7-series pumps found on many mid-range marine engines and auxiliary power units. If you've spent any time on the water, you know that a failing impeller means a failing engine—and nothing ruins a day on deck faster than overheating in the middle of nowhere. This OEM-grade impeller is engineered to restore full cooling circulation and prevent the catastrophic damage that occurs when raw-water cooling systems lose prime or flow.

Built from oil-resistant Nitrile rubber, the Johnson Pump F7B impeller features a 2.56-inch outer diameter with a spline-drive inner bore and a 1.98-inch width, matching original equipment specifications exactly. Nitrile construction offers superior durability against fuel, saltwater, and engine oils compared to standard elastomers, extending service life in harsh marine environments. The flexible vane design creates positive displacement as it rotates, drawing seawater or freshwater coolant through the pump housing and into the engine's cooling jacket—a simple mechanism that must function flawlessly to prevent thermal stress and corrosion inside your block.

Any boater running an F7-series Johnson Pump should inspect and replace the impeller every 3–5 years or after heavy use in sandy or silty water; proactive replacement during routine haul-outs prevents emergency repairs at sea. Installation is straightforward for anyone comfortable with basic pump service—slide the new impeller onto the drive shaft, align the splines, and reassemble the pump body. Whether you operate a cruising yacht, commercial fishing vessel, or auxiliary engine, keeping a spare Johnson Pump F7B impeller aboard is insurance against one of the most common causes of engine failure in recreational and professional marine use.