Seawater System - Volvo TAMD74C Operator's Manual

Seawater system

The seawater system is the engine's external cooling system. The seawater pump draws in water via the seawa-
ter intake and pump it on through the charge air cooler, heat exchanger and the reverse gear oil cooler. The sys-
tem is protected against galvanic corrosion by zinc anodes located in the charge air cooler, heat exchanger and
the reverse gear oil cooler.
WARNING! There is a risk that water will enter while working on the seawater system (if the boat is in the
water). Water may flow into the boat if a hose, plug or similar object located below the waterline is removed.
So always close the seawater cock. If the boat does not have a seawater cock, the flow of water must be
stopped in a safe manner. The boat must be brought up on land if this is not possible.
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Maintenance: Seawater system
Zinc anodes. Check/Change
WARNING! Risk of water entering. Close the sea-
water cock before starting work on the seawater
system.
1. Close the seawater cock.
2. Open drain tap (1) on the reverse gear oil cooler
and drain off the sea water.
3. Remove the zinc anode in the reverse gear oil
cooler (2), in the heat exchanger (3) and in the
charge air cooler (4).
NOTE! The sea water in the heat exchanger and
charge air cooler is drained at the same time.
4. Change the anode if less than 50% of its original
size. Otherwise, clean the anode with emery cloth
to remove the layer of oxide.
IMPORTANT! Do not use a wire brush or oth-
er metal tool for cleaning as this can impair
the galvanic protection.
5. Fit the zinc anodes. Make sure there is good con-
tact between the anode and the metal goods.
6. Close the drain cock (S).
7. Open the seawater cock before starting the en-
gine.
8. Make sure there are no leaks.
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