Installation manual
COOLING
SYSTEM
F1RESH
WATER
COOLING
CIRCUIT
NOTE:
Refer
to
the ENGINE COOLANT section
for
the rec-
o:mmended antifreeze
and
water mixture
to
be used as the
flesh 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,
t6
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 thennostat
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
c:ooling
system.
KEEP
THE
TO
COOLANT
F1EGOVERY
TANK
COOLANT
PASSAGE
CLEAR
FROM
COOLANT
RECOVERY
TANK
COOLANT
EXPANSION
~
\I
PRESSURE
yeAP
COOLANT
RETRACTION
NOTE:
Periodically check the condition
of
the manifold
pressure cap. Ensure the upper
and
lower rubber seals are in
good
condition. Check
to
ensure
the vacuum valve opens
and
closes tightly. Carry a spare
cap.
Check also to ensure the
coolant passage
is
clear so
coolant within the system
is
able to expand
and
contract
to
andfrom
the coolant recovery tank.
Coolant
Recovery
Tank
The coolant recovery tank allows for the expansion and con-
traction
of
the engines coolant duqng engine operation with-
out introducing air into the system. This recovery tank 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.
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
coaling
system
maintenance
is
critical;
a
substantial
number
of
engine
failures
can
be
traced
back
to
cooling
system
co"osion.
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
coo/ant.
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.
Engines
~
~enerators
15