Section II. FUEL SYSTEM
62.
General
The diesel fuel system consists of' a 100-galIon fuel tank, primary fuel filter, secondary fuel filter, fuel primer, fuel
injection pump, engine overspeed governor, fuel injectors, air cleaner, intake manifolds, ether starting aids, and the
necessary lines and fittings for distributing the diesel fuel to the components of the fuel system.
63.
Air Cleaner
a. Removal. Remove the air cleaner and pipe as instructed on figure 19.
b. Disassembly.
(1) Remove the air cleaner indicator (par. 60).
(2) Disassemble the air cleaner as illustrated on figure 20.
c. Cleaning, Inspection, and Repair. Clean and inspect all parts. Replace gaskets. Repair or replace all damaged
parts.
d. Reassembly.
(1) Reassemble the air cleaner as illustrated on figure 20.
(2) Install the air cleaner indicator (par. 60).
e. Installation. Install the air cleaner and pipe in reverse of instructions on figure 19.
64.
Intake Manifolds
a. Removal.
(1) Remove the air cleaner pipe (par. 63).
(2) Remove the two intake manifolds as instructed on figure 21.
b. Cleaning and Inspection. Clean and inspect all parts. Replace any damaged or defective parts.
c. Installation.
(1) Install the two intake manifolds in reverse of instructions on figure 21.
Note. Correct torque for manifold nuts is 50-55 foot-pounds.
(2) Install the air cleaner pipe (par. 63).
65.
Fuel Injectors
a. General. A characteristic of the Roosa-Master fuel injection pump is, that if engine misfiring is traced to a
cylinder in which no combustion is taking place, the cause may be an injector nozzle valve sticking open in the cylinder
which immediately precedes that cylinder in the engine firing order. During injection to the cylinder which has the nozzle
valve sticking open, fuel rushes into that cylinder with no restriction, causing a scavenging effect in the pump distributor
rotor. This causes a partial loss in fuel pressure to the following injector, the nozzle fails to open, and combustion does
not occur in that cylinder.
b. On-Equipment Testing.
(1) Start and operate engine at idle speed (TM 5-3820-205-10/2).
(2) Momentarily loosen injector fuel line assembly (fig. 5) on each injector in turn. Note fuel injector where
loosening of fuel line assembly causes no effect on engine operations.
Warning: Keep hands away from escaping fuel spray when loosening injector fuel line assemblies.
(3) Stop the engine and replace the injector noted in (2) above.
(4) Start the engine as in (1) above. If the operation is still erratic, determine the firing order (par. 4b) and
replace injector that injects immediately prior to fuel injector found in (2) above.
c.
Removal. Remove the six fuel injectors as instructed on figure 21.
d.
Cleaning and Inspection. Clean and inspect all parts. Replace the gaskets and all damaged parts.
e.
Installation. Install the fuel injectors in reverse of instructions on figure 21.
f.
Testing.
(1) Remove one fuel injector from the engine, leaving the fuel line connected to the fuel injection pump.
(2) Start the engine (TM 5-3820-205-10/2).
(3) Hold a target 12 inches from the nozzle end and observe the spray pattern for deflected spray or a spray
pattern that is not symmetrical.
(4) Inspect the nozzle for dripping or leaking around the capnut.
AGO 8156A
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