Cooling System; Changing Coolant - Westerbeke 12C- TWO Operator's Manual

COOLING SYSTEM
FRESH WATER COOLlN.G I;I{lCUIT
Ftesh
w:at~r
coolant is pumped through the engine
by
a
'circulating pump, absorbing heat from the engine. The
coolant then passes through the .thermostat into the manifold,
to 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 warms up, the
thermostat gradually opens, allowing
full
flow of the engine's
coolant to flow unrestricted to the external portion of the
cooling system . •
ENGINE COOLANT
WESTERBEKE recommends a mixture of 50% antifreeze
and 50% distilled water. bistilled water is free from the
chemicals that can corrode internal engine surfaces.
The antifreeze performs a double duty. It allows
the
engine
to run at proper temperatures by transferring heat away from
the engine to the coolant and lubricates
and
protects the
cooting circuit from rust and corrosion. Look for a good
quality antifreeze that contains Supplemental Cooling
Additives (SCAs) that keep the antifreeze chemically bal-
anced, crucial to long term protection.
NOTE:
Lookfor the new environmentally friendly long lasting
antifreeze that is now available.
The recommended 50/50 mixture will protect the engine
against the most extreme temperature. The antifreeze mixture
will also retard rust within the engine and add to
the
life of
the circulating pump impeller and seals.
A proper 50/50 mixture as recommeI!ded will protect the
engine coolant to temperatures of - 40'F.
Coolant Recovery Tank
The coolant recovery tarik allows for the expansion aJ!d con-
traction of the engines coolant during engine operation with-
outintroducing
air
into the system. This recovery tarik is
provided with fresh water cooled models and with the fresh
water coolant conversion kit and must be installed before
operating the engine.
. NOTE:
This tank, with its short run of plastic hose, is best
located at or above the level of the engine's manifold.
·NOTE:
Periodically check the condition of the pressure cap.
Ensure thot the upper and lower rubber seals are in good
condition and check that the vacuum valve opens and closes
tightly. Carry a spare 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.
Drain the engine coolant by removing the block drain adja-
cent to the oil filter, remove the in-board drain plug on the
heat exchanger and ·remove the pressure cap from the water
jacketed exhaust manifold.
BLOCK
. . COOL
DRAIN
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Refillil1gthe.;~oolant
After closing
the
engine drains, pour clean, preri:rixed coolant
into the manifold, start the engine and run it at a slow idle.
Monitor the coolant in the manifold and add as needed. Fill
the manifold to the filler neck and when the coolant is
flowing, install the pressure cap.
Remove the cap on
the
coolant recovery tarik 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 tarik.
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 tarik if
needed. Clean up any spilled coolant
A
CAUTION:
The engine "",ust be allowed to cool
down before attempting these procedures. Not only is
the sud ace of the engine hot but coolant temperatures
can be at 190'F.
A
CAUTION:
Proper cooling system maintenance is
critical; a substantial number of engine failures can be
tracedbackto cooling lIystem corrosion.
ElJ.gJn_t!~
& Generators
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