Installation 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
circu-
lating
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 mani-
fold from overheating). As the engine warms up, the thermo-
stat 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.
NOTE:
Periodically check the condition
of
the manifold pres-
sure cap. Ensure that the upper
and
lower rubber seals are
in
good
condition
and
check that the vacuum valve opens and
closes tightly. Carry a spare cap.
TO
COOLANT
RECOVERY
TANK
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 removmg
the
dram
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.
FROM
COOLANT
•
RECOVERY
TANK
COOLANT
EXPANSION
COOLANT
RETRACTION
SEALS
CHECKING
THE
PRESSURE
CAP
-...v-
WESTERBEKE
Engines
&
Generators
15