Cummins/Onan — Replacing the Sea Water Pump Impeller
Maintenance
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan MDKAA, Cummins/Onan MDKAB, Cummins/Onan MDKAL, Kubota D1005 engine, Kubota D1105 engine, Kubota V1305 engine, Kubota V1505 engine
Before you start
- Do not lubricate with petroleum products like grease and oil which attack impeller materials.
Procedure
- Disconnect negative battery cable(s).
- Close the sea cock and remove impeller cover and O-ring.
- Grip vanes on opposite sides with two pairs of pliers and pull out old impeller.
- Clean out impeller pieces from heat exchanger and exhaust elbow if vanes broke.
- Install new impeller, twisting clockwise; vanes incline counterclockwise.
- Wet inside of pump and impeller with water, soap or silicone lubricant; secure O-ring and cover.
- If strainer above waterline, fill strainer with water and reinstall cover.
- Open sea cock, reconnect battery cables (negative last) and start genset.
Tools required
- Two pairs of pliers Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Shut down within 30 seconds if no water flow from exhaust hull fitting
Full service-parts list: Cummins/Onan MDKAA →, Cummins/Onan MDKAB →, Cummins/Onan MDKAL →, Kubota D1005 engine →, Kubota D1105 engine →, Kubota V1305 engine →
Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.