Detroit Diesel — Service the Raw Water Pump (Impeller and Seal)
Repair & overhaul
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- If the impeller is reuseable, exercise care to prevent damage to the splined surfaces.
Procedure
- Remove the cover and gasket.
- Note the impeller blade position; grasp blades and pull the impeller off the shaft.
- Remove the neoprene spline seal(s) by pushing a screwdriver through the impeller.
- Remove the cam retaining screw and withdraw the cam and wear plate assembly.
- Remove the seal assembly (V-type) with hooked wires, or drill two holes in the seal case (in-line).
- Clean and inspect the impeller, cam and wear plate assembly and water seal.
- Install the seal assembly, cam and wear plate assembly.
- Apply a non-hardening sealant to the cam retaining screw and hole; secure the cam.
- Press the impeller onto the splined shaft with blades correctly positioned for rotation.
- Install the neoprene splined seal(s); turn the impeller several revolutions.
- Affix a new gasket and install the pump cover.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Detroit Diesel 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.