Volvo Penta 5.7 Gil-B, Operator'S Manual

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Maintenance and Care
Cooling System
The cooling system is a seawater system (optionally, a closed cooling system is available). The engine seawater pump
(mounted on front of the engine) sucks in water through the water inlets located on both sides of the lower gear unit.
Water pumped to the engine by the seawater pump is circulated through the engine by the engine circulating pump. A
thermostat determines the amount of water to be taken in, recirculated, and discharged to control engine operating
temperatures. Water is discharged through an idle exhaust relief and with exhaust through the propeller hub. A tempera-
ture gauge located on your boat instrument panel will indicate if the engine overheats. Do not operate engine without
thermostat.
IMPORTANT If engine should overheat, turn off engine and look for obstructions to water pickup. If any obstructions are
found, clear the obstruction and run engine again at 1500 RPM in neutral and check temperature gauge to verify condi-
tion. If overheating still occurs, return to port at low RPM to prevent excessive overheating and engine damage. See your
Volvo Penta dealer for service assistance.
If there is a risk of the air temperature reaching frost levels, the cooling system must be drained.
When laying up the boat for the winter, it is important that the cooling system be flushed with freshwater so that deposits
do not dry and also to prevent the buildup of salt crystals.
Draining Cooling System (Raw Water
System)
Draining the cooling system before the air temperature
drops below freezing will prevent damage to its
components. Perform this procedure with the boat out
of water.
When draining the engine, raise or lower the
bow of the boat in order to level the engine. This will
provide for complete drainage of the engine block and
exhaust manifold. If the bow of the boat is higher or lower
than the stern, some water may be trapped in the block.
Remove flush adapter cap ( A ).
Connect a garden hose to the flushing adapter and flush
the cooling system for 5 minutes.
Disconnect the garden hose and lower engine flush hose
alongside block and drain completely.
Reinstall the flush hose and cap in original locations.
Remove drain plugs from exhaust manifolds ( B ), (both
sides of the engine) and let drain completely. If manifolds
do not drain when plug is removed, use a small piece of
wire to clear and debris that may be blocking the drain.
Reinstall the drain plug and torque to 29 N•m (22 lb.ft.).
Loosen and slide clamps back. Disconnect hoses from
water pump and let the water run out. Turn the engine over
with the starter motor for a second (
do not allow the
engine to start! ) so that the water remaining in the
seawater pump comes out.
Reattach water pump hoses.
Caution!
Reconnect the hoses to their original locations.
Do not switch the hoses. The raw water pump
impeller will be damaged if improperly recon-
nected.
A
B
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