Fresh Water Pump - Yanmar 4LHA-HTP Operation Manual

Chapter 6 Cooling Water System

3. Fresh Water Pump

3. Fresh Water Pump
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, im-
peller, 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
Water temperature switch
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
6-7
lubricated ball bearings and cannot be disassembled.
OPTION
Water temperature switch
4LHA Seri,
Vbelt