Installation manual
COOLING
SYSTEM
FRESH
WATER
CIRCUIT
NOTE:
Refer to
ENGINE
COOLANT
section
for
the recom-
mended 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 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.
Coolant
Recovery
Tank
The
coolant recovery tank allows for engine coolant
expansion
and
contraction during engine operation, without
the introduction
of
air into the cooling 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
pressure cap, its rubber seals
and
the vacuum return valve.
Ensure the passage from the filler neck to the recovery tank
connection is kept clear.
MANIFOLD
PRESSURE
CAP
15
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 block drain plug
(right side
of
the block
just
above the oil pressure sensor) and
opening the manifold pressure cap. Flush the system with
fresh water, then reinstall the drain plug and refill the system.
NOTE:
The drain plug on the heat exchanger can also be used
to 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. Slowly pour clean, premixed
antufreeze coolant into the water jacketed exhaust manifold
filler neck opening. Fill the system full, then start the engine.
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.
KEEP
THESE
PASSAGES
CLEAR
TO
ENSURE
COOLANT
EXPANSION
A
FULL
FLOW
OF
COOLANT
TO
AND
FROM
THE
COOLANT
RECOVERY
TANK
(A
PIPE
CLEANER
WORKS
WELL)