Volvo Penta PENTA Launch Manual page 9

Check the freezing point of the coolant
with a hydrometer and top up the cooling
system if necessary. The coolant mixture
looses its corrosion protective qualities with time
and should therefore be changed every other year.
Avoid mixing different types of coolants since
N.B.
it drastically diminishes the corrosion protective
qualities.
Do not mix coolant with other additives.
Check and clean sea water filter, if fitted. Inhibit the
sea water cooled part of the engine in accordance
with the section on sea water cooled engines (see
page 7).
Check the level of the fresh water
system and make sure that all plugs
and draining cocks are fully closed.
Some engines have zinc anodes on the plugs
N.B.
and these act as sacrificial anodes in the cooling
system. An anode must be replaced when about
50% of its volume has been used up.
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