Figure 11C-27. Cleaning Injector
Figure 11C-28. Cleaning Spray Tip
Spray Tip
Orifices
(see Figure 11C-30 on page 11C-18).
Inspect both ends of the spill deflector
Use care to minimize removing metal or
for sharp edges or burrs which could
setting up burrs on the spray tip seat.
treate burrs on the injector body or in-
Remove only enough metal to produce a
jector nut and cause particles of metal to
clean uniform seat to prevent leakage be-
be introduced into the spray tip and
tween the tip and the nut. Carefully
valve parts. Remove burrs with a 500
insert carbon remover J 9418-1 in the in-
grit stone.
jector nut. Turn it clockwise to remove
the carbon deposits on the flat spray tip
Inspect the follower spring for visual de-
seat.
fects. Then check the spring with
s p r i n g tester J 22738-02
Wash the injector nut in clean fuel oil
and dry it with compressed air. Carbon
The injector follower spring (0.142" di-
deposits on the spray tip seating sur-
ameter) has a free length of approximate-
faces of the injector nut will result in
ly 1.504" and should be replaced when a
poor sealing and consequent fuel leakage
load of less than 70 Ibs. will compress it
around the spray tip.
to 1.028".
When handling the injector plunger, do
Check the seal ring area on the injector
not touch the finished plunger surfaces
body for burrs or scratches. Also check
with your fingers. Wash the plunger
the surface which contacts the injector
and bushing with clean fuel oil and dry
bushing for scratches, scuff marks or
them with compressed air. Be sure the
other damage.
If necessary, lap this
high pressure bleed hole in the side of
surface. A faulty sealing surface at this
the bushing is not plugged. If this hole
point will result in high fuel comsumption
is plugged, fuel leakage will occur at the
and contamination of the lubricating oil.
upper end of the bushing where it will
Replace any loose injector body plugs or
drain out of the injector body vent and
a loose dowel pin. Install the proper
rack holes, during engine operation,
number tag on a service replacement in-
causing a serious oil dilution problem.
jector body.
Keep the plunger and bushing together
as they are mated parts. After washing,
Inspect the injector plunger and bushing
submerge the parts in a clean receptacle
for scoring, errosion, chipping or wear.
containing clean fuel oil.
Check for sharp edges on that portion of
the plunger which rides in the gear.
Remove any sharp edges with a 500 grit
stone. Wash the plunger after stoning
I n s p e c t Injector Parts
it. Injector Busing lnspectalite J 21471
Inspect the teeth on the control rack and
can be used to check the port holes in
the control rack gear for excessive wear
the inner diameter of the bushing for
cracks or chipping. Slip the plunger in-
or damage. Also check for excessive
wear in the bore of the gear and inspect
to the bushing and check for free
the gear retainer. Replace damaged or
movement. Replace the plunger and
bushing as an assembly if any of the
worn parts.
above damage is noted, since they are
m a t e d parts. Use new mated factory parts
Inspect the injector follower and pin for
wear.
Fuel System and Governor
