Cooling System; Changing Coolant - Westerbeke 8.0KW-60HZ Operator's Manual

COOLING SYSTEM
FRESH WATER COOLING CIRCUIT
NOTE:
Refer to the ENGINE COOLANT section for the
recommended antifreeze and water mixture to be used as the
fresh water coolant.
Fresh water coolant is pumped through the engine by a
circulating pump, absorbing heat from the engine. The
coolant then passes through the thermostat into the heat
exchanger where it is cooled, and returned to the engine
block via the suction side of the circulating pump.When the
engine is started cold, external coolant flow is prevented by
the closed thermostat (although some coolant flow is
bypassed around the thermostat to prevent the exhaust
manifold from overheating). As the engine'watms up, the
thennostat gradually opens, allowing full flow of the engine's
coolant to flow unrestricted to the external portion of the
cooling system.
Coolant Recovery Tank
A coolant recovery tank allows for engine coolant expansion
and contraction during engine operation, without any signifi-
cant loss of coolant and without introducing air into the cool-
ing system. This tank should be located at or above the
engine manifold level and should be easily accessible.
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NOTE:
Periodically check the condition of the manifold pres-
sure cap. Ensure that the upper and lower ntbber seals are in
good condition and check that the vacuum valve .opens and
closes tightly. Carry a spare cap.
SEAL
MANIFOLD
PRESSURE
CAP
CHANGING COOLANT
The engine's coolant must be changed according to the
MAINTENANCE SCHEDULE. If the coolant is allowed to
become contaminated, it can lead to overheating problems.
A
CAUTION:
Proper cooling system maintenance is
critical;
a
substantial number of engine failures can be
traced back to cooling system corrosion.
Drain the engine coolant by removing the drain plug on the
engine block and opening the manifold pressure cap. Flush
the system with fresh water, then reinstall the drain and start
the refill process.
NOTE:
The drain petcock on the heat exchanger should also
be used to help drain engine coolant.
A
WARNING:
Beware of the hot engine coolant.
Wear protective gloves.
Refilling the Coolant
After replacing the engine block drain plug, close the heat
exchanger's coolant petcock. Then run the engine at idle and
slowly pour clean, premixed coolant into the manifold.
Monitor the coolant in the manifold and add as needed. Fill
the manifold to the filler neck and install the manifold
pressure cap.
Remove the cap on the coolant recovery tank and fill with
coolant mix to halfway between LOW and MAX and replace
the cap. Run the engine and observe the coolant expansion
flow into the recovery tank.
After checking for leaks, stop the engine and allow it to cool.
Coolant should draw back into the cooling system as the
engine cools down. Add coolant to the recovery tank if
needed and check the coolant in the manifold. Clean up any
spilled coolant.
COOLANT RETRACTION
COOLANT EXPANSION
TO COOLANT RECOVERY
TANK
Engines & Generators
14