Water Pumps; Water Intake Strainer - Westerbeke 3.5KW SBCG-60Hz Operator's Manual

COOLING SYSTEM
I
WATER PUMPS
DESCRIPTION
The fresh water cooling system has the raw water pump
mounted above the fresh water (coolant) pump as illustrated.
These pumps are self-priming, rotary pumps, with
non-ferrous housings and Neoprene impellers. The impellers
have flexible blades that wipe against a curved cam plate
within the impeller housing, producing the pumping action.
These pumps can not be allowed to run dry.
There should
always be a spare impeller and impeller cover gasket aboard
(an impeller kit). Water pump impeller failures occur when
lubricant (water) is not present during engine operation. Such
failures are not warrantable, and operators are cautioned to
make sure water flow is present at start-up. Water pumps
should be inspected periixlically for broken or tom impeller
blades. See
MAINTENANCE SCHEDULE.
NOTE:
Should a failure occur with the pumps internal parts
(seals and bearings) it may be more cost efficient to purchase
a new pump and rebuild the original pump as a spare.
PUMP COVER
INSPECT THE INSIDE
SURFACE FOR WEAR.
IMPELLER
FIT THE HUB SCREW
INTO THE SHAFT SLOT
WHEN ASSEMBLlNG,COAT
THE IMPELLER AND O-RING
WITH GLYCERIN
CHANGING THE WATER PUMP IMPELLERS
Remove the cover screws and the cover will separate the
upper pump (raw water) from the fresh water (coolant) pump
as shown in the illustration. Close the raw water thru hull
seacock. This will prevent water syphoning out of the pump
while the impeller is being changed.
1. Remove the wear plate to expose the impeller. Notice the
direction the impeller blades are working in so as to
install the replacement impeller with blades working in
the same direction.
.2. Using pliers, grab the impeller hub and withdraw the
impeller from the pump. Inspect the inside of the pump,
the cam, the inner wear plate, and the inside surface of the
cover plate for wear. Replace any worn components.
3. Wipe the inside surface of the pump dry. Apply a film of
glycerin supplied in the impeller kit to the inside pump
surfaces and to the exposed area of the shaft lip seal.
4. Install the new impellers with a rotating motion so the
blades are working in the same direction as those of the
removed impeller.
5. Apply glycerin to the O-ring, impeller, gasket, the wear
plate and assemble into the pump housing. Reassemble
the upper pump (raw water) making certain the fasteners
are tight. Re-install any hoses that were removed.
6. Run the engine to make certain both pumps are operating
properly. The engine should run at proper temperature.
raw water should discharge from the exhaust and there
should not be any leaks around the pumps.
A
WARNING:
When the engine is started, make
sure that the pumps are pumping within 30 seconds
after engine start. If not, "stop" the engine at once
and couect the problem.
To increase the service life of the impeller, do not install
them in the pump if the engine will be in storage for
. longer than 3 months. Store the impellers in a dark, cool, and
dry location. Replace the cover plate on the pumps securely
and ensure the thru hull seacock is closed.
WATER INII'KE STRAINER
A water intake strainer (raw water) is a required component
when the generator is installed. Refer to the previous page
for details.
TYPICAL RAW WATER STRAINER
(OWNER
INSTALLED)
INCOMING
RAW WATER
,
SHOULD A PUMP SHAFT SEAL LEAK,
r..J~---THIS DRAIN TUBE WILL ALLOW THE
WIPE THIS SURFACE CLEAN
BEFORE INSTALi.JNG THE
COVER
DRAIN TUBE
LEAK TO DRAIN AWAY FROM THE
UNII KEEP THIS TUBE CLEAR
. OF OBSTRUCTIONS.
Engines & Generators
18
SEACOCK
~
INSPECT AND
CLEAN EVERY
100 HOURS