TM 5-3810-300-24&P-3
Fuel Injector
2.1.1
follower to the bottom of its stroke. Then very slowly
6. Swing the mounted injector and adapter plate inward
release the pressure on the handle while moving the control
until they contact the stop pin at the rear of the support
rack up and down as shown in Fig. 8 until the follower
bracket.
reaches the top of its travel. If the rack does not fall freely,
loosen the injector nut, turn the tip, then retighten the nut.
Clamping the Fuel Injector
Loosen and retighten the nut a couple of times if necessary.
Generally this will free the rack. Then, if the rack isn't free,
1. Refer to Fig. 13 and position the injector tester levers as
change the injector nut.
In some cases it may be
follows:
necessary to disassemble the injector to eliminate the
cause of the misaligned parts.
Lever 2 up and to the rear
Visual Inspection of Plunger
Lever 3 in the rear detent
An injector which passes all of the previous tests should
Lever 4 up (horizontal)
have the plunger checked visually, under a magnifying
glass, for excessive wear or a possible chip on the bottom
Lever 5 up (horizontal)
helix. There is a small area on the bottom helix and lower
portion of the upper helix, if chipped, that will not be
2. Align the clamping head nylon seals over the injector
indicated in any of the tests.
filter caps.
Remove the plunger from the injector as follows:
3. Back off the Thru-Flow valve about half-way to allow the
self-aligning nylon seals to seat properly during the
1. Support the injector, right side up, in holding fixture J
clamping operation.
22396.
4. Hold the clamping head in position over the filter caps
2. Compress the follower spring. Then raise the spring
and, with the left hand, operate pump lever 1 evenly to
above the stop pin with a screw driver and withdraw the pin
move the clamping head down to seal the filter caps.
(Fig. 9). Allow the spring to rise gradually.
NOTE: The Thru-Flow valve should still
3. Remove the injector from the holding fixture. Turn the
turn freely. If it does not, turn the valve
injector upside down, to prevent the entry of dirt, and catch
counterclockwise until it rotates freely and
the spring and plunger as they drop out.
re-apply clamping pressure.
4. Inspect the plunger. If the plunger is chipped (Fig. 10),
CAUTION: Excessive force on lever I
replace the plunger and bushing assembly.
during clamping can damage the seals in
the valves operated by levers 4 and 5.
5. Reinstall the plunger, follower and spring.
Purging Air from the System
Installing Fuel Injector in Tester J 23010
Move lever 4 down and operate pump lever I to produce a
1. Select the proper clamping head (Fig. 11). Position it on
test oil flow through the injector. When air bubbles no
the clamping post and tighten the thumb screw into the
longer pass through the clear discharge tubing, the system
lower detent position (Fig. 12).
is free of air and is now ready for testing.
2. Connect the test oil delivery piping into the clamping
Injector Valve Opening and Spray Pattern Test
head.
This test determines spray pattern uniformity and the
3. Connect the test oil clear discharge tubing onto the pipe
relative pressure at which the injector valve opens and fuel
on the clamping head.
injection begins.
4. Locate the adapter plate on top of the support bracket by
1. Clamp the injector properly and purge the air from the
positioning the 3/8"diameter hole at the far right of the
system.
adapter plate onto the 3/8" diameter dowel pin. This allows
the adapter plate to swing out for mounting the fuel injector.
2. Move lever 4 down.
5. Mount the injector through the large hole and insert the
injector pin in the proper locating pin hole (Fig. 11).
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