TM-9-2815-200-35
ENGINE, WITH CONTAINER:TURBOSUPERCHARGED, DIESEL ,FUEL INJECTION ,90-DEGREE “V” TYPE, AIR - COOLED ,12 - CYLINDER , ASSEMBLY ;MODELS AVDS-1790-2M (2815-856-4996), AVDS-1790-2A AND AVDS-1790-2AM (2815-856-9005)
TECHNICAL MANUAL; DIRECT SUPPORT, GENERAL SUPPORT AND DEPOT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS
TM-9-2815-200-35 - Page 51 of 779
c. Oil Pump.
The oil pump assembly consists
of three sections combined as a single unit. The
twin scavenge oil pump section of the unit picks
up oil from the front and rear compartments of
the oil pan and delivers it to the main pressure
pump oil compartment. The main pressure oil
pump section picks up oil from its respective
compartment and supplies oil to the engine oil
galleries and bearings. The piston cooling oil
pump section picks up oil from the rear sump
section of the oil pan and supplies oil to the
piston oil sprayer nozzles (a, above).
d. Oil Filters and Control Valves.
The main
and auxiliary oil filters (figs. 1-3 and 1-6) and
the bypass valves are located in the crankshaft
damper and oil filter housing at the front of the
engine. All engine oil passes through a screen
type main oil filter. Engine oil, which lubricates
the fuel injection pump and the two tur-
bosuperchargers (figs.
1-1, 1-2, and
1-4), is
further filtered by a replaceable element type
auxiliary oil filter. Two oil filter bypass valves
are used, one for the main oil filter and one for
the auxiliary oil filter. The main oil filter bypass
valve opens at a differential pressure of 35.6 psi
and the auxiliary oil filter bypass valve at a
differential pressure of 15 psi. The bypass valves
permit oil to bypass the filters in the event that
they become clogged.
1-18. Fuel System
a.
Fuel Supply Pump Assembly. The engine
driven vane type fuel supply pump assembly
(figs. 1-3 and 1-6) is used to supply fuel under
pressure to the fuel injection pump. The fuel
pump is crankshaft driven by the fuel pump
drive adapter (SS, fig. 1-8) and the drive
coupling (RR ) located at the front of the engine.
b. Fuel Injection Metering Pump.
The fuel in-
jection metering pump is located in the “V” of
the engine between the fan drive housings, and
supplies fuel under high pressure to each
cylinder. The pump is driven at engine speed
from the fan drive housing located at the rear of
the engine. A fuel injector pump advance
assembly (J, fig.
1-8) is incorporated in the
accessory drive housing to automatically provide
a gradual degree advance of injection timing
during the engine speed range from idle to 1800
rpm.
c. Fuel Injector Nozzles and Tubes.
Twelve
fuel injector nozzles (fig. 1-11), one per cylinder,
are used to inject fuel into the combustion
chambers, Twelve fuel injector tubes of equal
length carry the fuel from the fuel injection
pump to the nozzles. The nozzles on each
cylinder bank are interconnected by fuel return
lines to provide a path for the return of excess
fuel.
d. Fuel Purge System.
A manually operated
purge pump is provided in the vehicle operator’s
compartment and is used to clear the engine
main fuel system and flame heater system of air,
and fill them with fuel. Purged air is forced
through the main fuel tubes into the fuel return
lines and on to the vehicle fuel tanks. The fuel
filters contain drain lines, with manually
operated valves, which are used to drain the
water from the filters, and for purging the fuel
system.
1-12
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