Detroit Diesel — Replace Raw Water Pump Seal and Impeller
Repair & overhaul
From a Detroit Diesel operator's manual — check it applies to your exact model before use.
Before you start
- Do not scratch lapped seal seat or shaft.
Procedure
- Remove cover screws; lift cover and gasket.
- Grasp impeller blades with pliers and pull impeller from shaft.
- Remove spline plugs by pushing screwdriver through impeller.
- Inspect impeller; replace if damaged or permanently set.
- Insert hooked wires between housing and seal; pull seal assembly from shaft.
- Remove seal seat and gasket.
- Remove cam bolt and cam; remove wear plate and check for wear; reverse if worn.
- Install wear plate, cam, seal seat and gasket.
- Place seal ring in ferrule; slide ferrule over shaft against seal seat.
- Install flat washer and marcel washer.
- Compress impeller blades and press impeller on splined shaft.
- Turn engine over a few revolutions; install spline plugs.
- Install cover with new gasket.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Detroit Diesel operator's 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.