Installation manual

COOLING
SYSTEM
FRESH
WATER
COOLING
CIRCUIT
NOTE:
Refer
to
the
ENGINE
COOLANT
page
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
thennostat
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
thennostat
(although
some
coolant
flow
is
bypassed
arouud
the
thennostat
to
prevent
the
exhaust
manifold
from
overheating).
As
the engine wanns
up,
the
thennostat
gradually
opens,
allowing
full
flow
of
the engine's
, coolant
to
flow
unrestricted
to
the external
portion
of the
cooling
system.
CoolantRecovery
Tank
A
coolant
recovery tank
allows
for engine
coolant
expansion
'"
al\d
contraction
during
engine
operation,
without
any
significant
loss
of
coolant
and
without
introducing
air
into
the
cooling
system.
This
tank
should be
located
at
or
above
the
engine
manifold
level
and
should be
easily
accessible.
COOLANT
'.
'.'w,"'"
RECOVERY
TAN,K
NOTE:
Periodically
check
the
condition
of
the
manifold
pressure
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.
CHECKING
THE
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.
Refer
to
the
illustration
below.
NOTE:
The
drain
petcock
on
the
heat
exchanger
can
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
engille
at
idle and
slowly
poor
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.
I
COOLANT
DRAIN
~
WESTERBEKE
Engines & Generators
16-
.