Yaroslavl Engine Plant YMZ-536 Operation Manual page 95

The engines are equipped with a fine fuel filter 1 installed on
the filter housing with its cap down (Fig. 31). The housing with the
filter is mounted on the left side of the cylinder block.
The replaceable filter (2 pcs.) is designed as a single-piece
shell with a metal housing.
To install the filter, screw it manually as far as it will go onto
the central threaded pipe union for the clean fuel outlet which is
screwed into the filter housing (see "Maintenance" section of this
Manual). The connection is sealed by the outer rubber ring of the
replaceable filter.
The transmitter installed on the filter housing in the clean fuel
channel serves to measure the fuel pressure and temperature in the
low-pressure line of the engine microprocessor control system.
The engines use a high-pressure fuel pump with a built-in
priming pump.
The pump has three HP sections (Fig. 33); each section is fed
through a dosage device with an electric valve. The sections are
located in the same plane and driven by the same cam on the pump
shaft. The maximum fuel pressure in the high-pressure line developed
by the pump is 1800 kgf/cm
The inside parts of the pump including the shaft slide bearings
are lubricated with fuel. For this reason on the pump shaft drive end
there are two sealing collars with a gap between them. In the gap area
there is a drain hole leading to the engine outside. Fuel coming out of
the drain hole is a sign of the pump side collar failure, whereas
presence of oil indicates failure of the engine side collar.
HIGH-PRESSURE FUEL PUMP
2
.
FINE FUEL FILTER
95