Overview

The Jabsco 18838-0001-P is a 12-blade neoprene replacement impeller kit for keyed-drive bronze flexible impeller pumps. It measures 2-7/16 in in diameter, 1-1/4 in in depth, uses a 5/8 in shaft diameter, and has a brass insert at the hub, so it should be matched to the impeller already in your pump rather than ordered by diameter alone.

This size is used in marine engine-cooling pumps and in some bilge, transfer, and general water-service pumps that use a bronze flexible impeller design. On a boat, it is the kind of service part that makes sense to replace on schedule and keep aboard as a spare, because a damaged impeller can cut water flow quickly and turn into a cooling problem just as fast.

Key features

• 12-blade neoprene impeller for keyed-drive bronze flexible impeller pumps
• Fit-critical dimensions: 2-7/16 in outside diameter, 1-1/4 in depth, and 5/8 in shaft diameter
• Brass insert at the hub
• Used in many marine pump applications including engine cooling, bilge duty, transfer duty, and general onboard water movement where this size is specified
• A practical spare to carry aboard when uninterrupted raw-water flow matters

Compatibility and fit

Fit comes down to four checks: outside diameter, impeller depth, shaft size, and drive style. This impeller uses a keyed drive, so it is not a substitute for spline-drive or pin-drive versions even when the outside diameter looks close.

Before ordering, compare the old impeller or the pump service data with the 2-7/16 in diameter, 1-1/4 in depth, 5/8 in shaft diameter, and 12-blade layout. That is the safest way to confirm the impeller will seat correctly in the housing and prime the pump as expected.

Installation and maintenance

When you change the impeller, pull the old one by the hub with the proper removal tool or with pliers that will not mark the pump body. Screwdrivers can scar the pump face and create leak paths at the cover.

Grease the new impeller lightly before installation so it slides into the bore more easily and has some protection during initial prime. After the cover is back on, check for normal prime and water flow right away. For boats that rely on raw-water cooling, replacing the impeller on a regular schedule is a lot easier than dealing with a failure underway.

Use on board

This part suits owners maintaining raw-water engine-cooling pumps and other bronze flexible impeller pumps that already call for this size and keyed hub pattern. It also makes sense as a spare for coastal cruising, fishing boats, and longer runs where loss of pump output can stop the day quickly.