Cummins/Onan 4MCCK / 605MCCK — Rubber Impeller Water Pump Repair
Repair & overhaul
For the Cummins/Onan 4MCCK / 605MCCK, from the Cummins/Onan service manual.
Applies to: Cummins/Onan 605MCCK, Cummins/Onan MCCK, Cummins/Onan MCCK engine
Before you start
- Do not remove the factory coating of high-aniline oil from the impeller.
- Use engine lubricating oil on the inside and outside diameter of the seat ring on the new seal before installation.
Procedure
- Remove the cover and gasket.
- Remove the impeller with pliers or by prying with a screwdriver, avoiding damage to the pump body.
- To install a new impeller, align the driving flat surface with the shaft flat surface; bend blades nearest the cam and insert.
- Remove the retaining ring, then pry the seal assembly through the drain slots.
- Remove the bearing and shaft assembly by striking the impeller end of the shaft with a brass or wood dowel.
- Install by the same method, striking the drive end of the shaft.
- Torque screws 15 to 17 in. lbs.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Torque screws 15 to 17 in. lbs.
Full service-parts list: Cummins/Onan 605MCCK →, Cummins/Onan MCCK →
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.