Volvo Penta D4 Operator's Manual page 82

Maintenance
80
Seawater System, Cleaning and
Inhibiting
The raw water system must be flushed with fresh
water, to prevent deposits and salt crystals from build-
ing up inside it. It must also be conserved when the
boat is laid up for winter/out of season storage so that
it is protected from internal corrosion.
WARNING!
Risk of water penetration.
Cleaning and inhibiting the seawater system should be
carried out with the boat on land.
WARNING!
Working with or going close to a running engine is a
safety risk. Watch out for rotating components and hot
surfaces.
1 On boats with reverse gears, open the sea cock.
2 Disconnect the hose from the raw water pump and
install a hose which goes to a bucket filled with fresh
water. Arrange re-filling.
IMPORTANT!
The impeller will be damaged if it is run dry.
3 Check that there is no one near the propeller and
no one will be splashed by the exhaust outlet.
4 Set the control lever to neutral and start the engine.
Let it run at fast idle for a few minutes. Stop the
engine.
5 Fill a bucket with a mixture of 40% glycol and 60%
fresh water, to conserve the system. Fix a container
at the exhaust outlet.
6 Start the engine and let it idle. Stop the engine just
before the mixture is used up. Repeat until the
entire system has been flushed with the mixture.
7 Put the raw water hose back.
8 The system has now been conserved. The glycol
mixture should remain in the system during stor-
age.
Before launching the boat, drain the mixture and
hand it to a re-cycling station for disposal
7748934 04-2008