Replacing Sea Water Impeller on QSD 4.2 Engine

By Ron Matuska — Adagio, 34-318


  • Remove belt cover, 2 small screws and 2 screws with nuts.
    • Be careful not to drop the metal spacers trapped in the rubber grommets.
  • Loosen, but do not remove 3 pump pulley bolts.
    • Belt tension will usually keep the pulley from turning when you loosen the bolts.
  • Remove serpentine belt, inspect and make note belt routing.
    • You can use ½ inch breaker bar but properly sized open end wrench will work.
  • Remove Pulley.
  • Place drip pan under pump to retain coolant.
  • Remove 2 water hoses.
  • Remove pump from engine, 2 Allen head bolts.
  • Remove pump rear cover bolts.
  • Replace impeller.
    • Note impeller vane direction for reinstallation.
  • Reverse order for assembly.
  • Test.


1. Start of Project   2. Cover Off, Serpentine Belt Routing

3. Pump, Pulley and Hoses
  4. Pulley Removed
5. Hoses Off   6. Sea Water Pump Off (Rear View)
  Click on Photos to Enlarge
7. Pump Cover Off    

Copyright © 2012 SENTOA • Last Update August 29, 2016 • Questions? Contact the SENTOA Officers.