Fresh Water Pump; Fresh Water Pump Construction - Yanmar 3JH4E Service Manual

9.3 Fresh water pump

9.3.1 Fresh water pump construction

The fresh water pump is of the centrifugal (volute)
type, and circulates water from the fresh water
tank to the cylinders and cylinder head.
The fresh water pump consists of the pump body,
impeller, pump shaft, bearing unit and mechanical
seal. The V pulley on the end of the pump shaft is
driven by a V belt from the crankshaft.
The bearing unit assembled in the pump shaft
uses grease lubricated ball bearings and cannot
be disassembled.
The totally enclosed mechanical seal spring
presses the impeller seal mounted on the impeller
side away from the pump body side. This prevents
water from leaking along the pump shaft.
As the impeller and pulley flanges are press fit
assembled, they cannot be disassembled.
Cylinder head
To cylinder block
O-ring
From heat exchanger
(fresh water tank)
267
9. Coolant system
Thermostat
Fresh water pump
Spacer
010653-00E
To heat exchanger
(fresh water tank)
For turbine coolant
joint and coolant
temperature switch
For sender unit
010700-00E