C
A
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TM 5-3805-258-24-1
F U E L
S Y S T E M
T E S T I N G A N D A D J U S T I N G
T E S T I N G A N D A D J U S T I N G
INSTALLING CARBON DAM
2. Carbon dam. 3. Saal. N. 8S2252 Carbon Seal Tool.
FUEL INJECTION LINES
Fuel from the fuel injection pumps goes to the fuel
injection nozzles through the fuel injection lines.
When fuel injection lines are disconnected or re-
moved, always put caps or plugs on the ends to keep
dirt out of the lines. When fuel injection lines are
installed, be sure all clamps and dampers are in-
stalled in their original location.
The nuts that hold a fuel injection line to an injec-
tion nozzle and injection pump must be tightened to
the correct torque. If the nut is loose, fuel will leak
from the connection. If the nut is tightened too tight,
the inside diameter of the line will become smaller
and cause a restriction to the flow of fuel in the line.
Use a torque wrench and a 5P144 Fuel Line Socket
to tighten the fuel injection line nuts to 40 ± 7 N.m
(30 ± 5 lb. ft.).
WARNING
Fuel injection lines which are bent, damaged or
rubbing can leak and cause a fire. Replace any
lines which have damage or leaks that can not
be corrected when tightened to the correct
torque.
CHECKING THE PLUNGER AND LIFTER
OF AN INJECTION PUMP
NOTE: There are no different size spacers available
to adjust the timing dimension of the fuel injection
pumps. If the pump plunger or the lifter is worn, they
must be replaced. Because there is no adjustment to
the timing dimension possible, there is NO OFF
ENGINE LIFTER SETTING PROCEDURE.
When there is too much wear on the fuel injection
pump plunger, the lifter may also be worn and there
will not be good contact between the two parts. To
stop fast wear on the end of a new plunger, install new
lifters in the place of the lifters that have wear.
WEAR BETWEEN LIFTER AND PLUNGER
Fig, A. Illustrates the contact surfaces of a new pump
plunger and a new lifter. In Fig. B the pump plunger end
lifter have worn considerably. Fig. C shows how the fist
end of a new plunger makes poor contact with a worn lifter,
rasulting in rapid wear to both parts.
An injection pump can have a good fuel flow com-
ing from it but not be a good pump because of slow
timing that is caused by wear on the bottom end of
the plunger. When making a test on a pump that has
been used for a long time, use a micrometer and
measure the length of the plunger. If the length of the
plunger is shorter than the minimum length (worn)
dimension given in the chart, install a new pump.
FUEL PUMP PLUNGER
Length (new) . . 73.886 f 0,013mm (2.9089 f ,0005 in,)
Minimum length (worn) . . . . . . . . 73.873 mm (2,9084 in.)
Look for wear at the top part of the plunger. Check
the operation of the plunger according to the instruc-
tions for the Fuel Injection Test Bench.
REMOVAL AND INSTALLATION OF FUEL
INJECTION PUMPS
Toole Needed:
8S4613 Wrench.
8S2244 Extractor.
7N1048 Timing Pin.
8V4166 Tlmlng Pin.
Removal of Fuel Injection Pumps
CAUTION
Before any parts are removed from the fuel
injection pump housing, thoroughly clean all
dirt from the housing. Dirt that gets inside the
pump housing will cause much damage.
NOTE: The fuel rack must be in the center position
before the fuel injection pumps can be removed.
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