Installation manual
COOLING
SYSTEM
FRESH
WATER
COOLING
CIRCUIT
NOTE:
Refer
to
the ENGINE
COOLANT
section
for
the rec-
ommended
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 pre-
vented 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
~olin~
s¥stem.
TOCOOuwr
RECOVERY
TANK
KEEP
mESE
PASSAGES
CLEAR
TO
ENSURE
A
FULL
FLOW
OF
COOLANT
TO
ANO
mOM
mE
COOLANT
RECOVERY
TANK
( A
PIPE
CLEANER
WORKS
WELL)
FROM
coouwr
RECOVERY
TANK
KEEP
THE
COOLANT
PASSAGE
CLEAR
COOLANT
RETRACTION
NOTE:
PeriodicaUy 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. CarlY a spare
cap.
Check also to ensure the
coolant
passage is clear
so
coolant
within
the,
system is
able to expand
and
cOn1ract
SEAL
to
and
from
the coolont recovClytank
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:
This tank, with its short I'U1I
of
plastic /wse, 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
cooling
system
maintenance
Is
crItIcal; a
substantial
number
of
engIne
failures
can
be
traced
back
to
cooling
system
corroSion.
Drain the engine coolant by loosening the drain plug on the
engine block and opening the manifold pressure cap. Flush
the system with fresh water, then start the refill process.
NOTE:
The drain on the heat exchonger should also be used
to
help.
drain engine
coolant.
ENGINE
BLOCK
~~
COOLANT
DRAIN
(19mm
HEX)
--fl
Refilling
the
Coolant
OIL
GALLERY
After closing the engine block drain, pour clean, premixed
coolant into the manifold and when the coolant is visible in
the manifold, start the engine and run it at slow idle.
Open
the air bleed petcocks on the manifold and the thermostat
housing.
Monitor the coolant in the manifold and add as needed. Fill
the manifold to the filler neck and when the coolant flowing
from the petcock is free
of
air bubbles, close the petcock and
install the 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.
When
the petcock on the thenno-
stat housing
is
free
of
air bubbles, close that petcock.
A.fter 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. Clean up any spilled coolant.
A
WARNING:
Beware
of
the
hot
engine
coolant.
Wear
protectIve
gloves.
Engines & Generators
14