Volvo Penta D4 Operator's Manual page 80

Maintenance. Seawater system
78
Checking/Changing sacrificial anodes
WARNING! Risk of water entering. Close the se-
awater cock before starting work on the seawater
system.
1. Close the seawater cock.
2. Drain the seawater as described in "Draining the
seawater system".
3. Remove the sacrificial anodes in the heat exchan-
ger and the intercooler.
4. Check the sacrificial anodes and change them if
they are less than 50% of their original size. Other-
wise, clean the sacrificial anodes with sandpaper
to remove the layer of oxide before refitting them.
IMPORTANT ! Clean with sandpaper. Use no
steel tools as this will impair electrical protection.
5. Fit the sacrificial anodes. Make sure there is good
contact between the anode and the metal goods.
6. Close the drain nipples.
7. Open the seawater cock before starting the engi-
ne.
8. Make sure there are no leaks.