Volvo Penta AD31, Owner'S Manual, Page: 32 / 45

IMPELLER
11
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.