Installation manual
ENGINE
COOLING
CIRCUIT
Changing
the
Raw
Water
Pump
Impeller
Close the raw water intake valve. Remove the pump covcr
and, with the aid
of
two
small screwdrivers, carefully pry the
impeller out
of
the pump. Install the new impeller and gasket.
Move the blades to conform to the curved
cam
plate and
push
the
impeller
into
the
pump's
housing. When
a<>sern-
bling, apply a thin coating
of
lubricant to the impeller and
gasket.
Open the raw water intake valve.
GASKET
RAW
WATER
PUMP
A
CAUTION:
If
any
of
the
vanes
have
broken
off
the
impeller,
they
must
be
found
to
prevent
blockage
in
the
cooling
circuit.
They
can
often
be
found
in
the
heat
exchanger.
HEAT
EXCHANGER
The
heat exchanger is a
copper
cylinder which encloses a
number
of
small
copper
tubes. Raw water
is
pumped through
the small copper tubes and the freshwater coolant from the
engine
is
circulated around the copper tubes.
The
raw water
removes heat from the freshwater coolant.
GASKET
OUT
DEBRIS
NEW
Zinc
Anode
CLEAN
AND
REUSE
REPLACE
REPLACE
A zinc anode, or pencil.
is
located
in
the raw water cooling
circuit within the heat exchanger. The purpose
of
the zinc
anode is to sacrifice itself to electrolysis action taking place
in
the raw water cooling circuit. thereby reducing the effects
of
electrolysis on other components
of
the system. The con-
dition
of
the zinc anode should be checked monthly and the
anode cleaned
or
replaced as required. Spare anodes should
be carried on hoard.
NOTE:
Electrolysis acrion is the result
of
each particular
installalion and vessel location; not that
of
the generator.
If the zinc pencil needs replacement, hold the hex boss into
which the zinc pencil
is
threaded with a wrench while loos-
ening the anode with another wrench. This prevents the hex
boss from possibly tearing off the exchanger
shell. After
removing the zinc, note the condition
of
it.
If the zinc
is
in
poor condition, there are probably a lot
of
zinc tlakes within
the exchanger. Remove the end
of
the heat exchanger and
clean the inside
of
all zinc debris. Always have a spare heat
exchanger end gasket
in
case the present one becomes
dam-
aged when removing the end cover. Replace the gasket (refer
to your engine model's heat exchanger end gasket part num-
ber), o-ring, cover, and install a new zinc anode.
Heat
Exchanger
Service
After approximately 1000 hours
of
operation, remove, clean
and pressure test the engine's heat exchanger. (A local auto-
motive radiator shop should be able
to
clean and test the heat
exchanger.)
NOTE:
Operating in silty and/or tropical walers may require
that a heat exchanger cleaning he performed more often than
every
1000 hours.
HEAT
EXCHANGER
[32
KW
SHOWN]
""'"
WESTERBEKE
Engines & Generators
15