Volvo Penta AD31 Owner's Manual page 32

The impeller pumps cooling water through the
engine cooling system. It is, therefore, an extremely
vital safety feature. Replace the impeller at least
every two years. However, a worn or damaged
impeller must be replaced immediately. Make a
habit of keeping a spare impeller, and seal for the
impeller pump cover, on board.
After inhibiting, unfasten the sea water
pump cover and remove the impeller.
Rinse it well and keep it in a tightly
sealed plastic bag in a cool place during the lay-up
period.
Install a perfect impeller and impeller
cover together with a new seal.
IMPELLER
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