71
EXTRACT THE RAW WATER PUMP IMPELLER
CAUTION !
If the engine has been run without supply of raw water,
check the raw water pump impeller. Change it if needed.
The service life of the raw water pump impeller vary
depending the operating conditions.
The raw water pump is an essential component of the
engine. A worn impeller could crack and damage the
cooling system. Always have a spare raw water pump
impeller on board.
TO REMOVE THE SEA WATER PUMP :
1. Close sea cock and drain sea water system.
2. Remove sea water outlet connection (
A
), remove sea
water pump cap screws (
B
) and remove pump.
3. Clean all gasket material from both mating surfaces.
4. Inspect gear teeth for damage. Install new gear (
D
) by
aligning key (
C
) to the pump shaft keyway.
S08
MAINTENANCE
5. Install pump overhaul kit.
6. Install lock washer (
E
) and hex nut (
F
) finger tight and
insure key is properly in place.
7. Tighten hex nut to specifications : 68 Nm (50 lb.-ft.).
8. Install sea water pump with new gasket to front plate
and thighten cap screws to specifications : 140 Nm (103
lb.-ft.).
TO REPLACE THE SEA WATER PUMP IMPELLER :
1. Remove cap screws and cover plate (A) from sea
water pump.
2. Remove impeller (B) from pump housing.
3. Remove O-ring (D).
4. Inspect cam plate (E) for evidence of heavy pitting or
wear. Replace as needed.
5. Inspect impeller for damages such as tears, stress
cracks, excess abrasions on vane ends, or chunks of
material missing. Impellers that are run dry will overheat
and fail the impeller blades at the root. Impellers that
swell and stick, fail the impeller in the middle of the
blade. If impeller replacement is necessary, order an
impeller repair kit.
8. Lubricate new impeller blades with a non-petroleum
based lubricant such as silicone or soapy water. Install
impeller using a twisting motion and be sure that the
impeller blades are bent in the same direction as they
were upon removal to prevent damage at startup. Rotate
impeller on shaft to align keyways and spines and slide
the impeller onto the shaft.
9. Using a new O-ring (D), install cover plate and cap
screws with washers and tighten to specifications : 35
Nm (26 lb.-ft.).
10. Open sea cock, start engine and check pump
operation.
Summary of Contents for N5.160 CR2
Page 2: ......
Page 4: ......
Page 40: ...40 NOTES...
Page 77: ...77 S08 MAINTENANCE INSTRUMENTS PANEL...
Page 103: ......
