2.1.1 Fuel Injector
DETROIT DIESEL 53
8. Withdraw the injector control rack from the injector
body. Also remove the seal ring from the body.
Clean Injector Parts
Since most injector difficulties are the result of dirt
particles, it is essential that a clean area be provided
on which to place the injector parts after cleaning. and
inspection.
Wash all of the parts with clean fuel oil or a suitable
Fig. 30 - Cleaning Injector Nut Spray Tip Seat
cleaning solvent and dry them with clean, filtered
compressed air. Do not use waste or rags for cleaning
Then raise the spring above the stop pin with a screw
purposes. Clean out all of the passages, drilled holes
driver and withdraw the pin. Allow the spring to rise
and slots in all of the injector parts.
gradually.
Carbon on the inside of the spray tip may be loosened
3. Refer to Fig. 24 and remove the plunger follower,
for easy removal by soaking for approximately 15
plunger and spring as an assembly.
minutes in a suitable solution prior to the external
cleaning and buffing operation. Methyl Ethyl Ketone
J 8257 solution is recommended for this purpose.
4. Invert the fixture and, using socket J 4983-01, loosen
the nut on the injector body (Fig. 25).
Clean the spray tip with tool J 9464-01 (Fig. 27).
5. Lift the injector nut straight up, being careful not to
CAUTION: Care must be exercised when
dislodge the spray tip and valve parts. Remove the
inserting the carbon remover J 9464-01 in the
spray tip and valve parts from the bushing and place
spray tip to avoid contacting the needle valve
them in a clean receptacle until ready for assembly.
seat in the tip.
When an injector has been in use for some time, the
Wash the tip in fuel oil and dry it with compressed
spray tip, even though clean on the outside, may not
air. Clean the spray tip orifices with pin vise J 4298-1
be pushed readily from the nut with the fingers. In this
and the proper size spray tip cleaning wire. Use wire
event, support the nut on a wood block and drive the
J 21460 to clean .0055 " diameter holes and wire
tip down through the nut. using tool J-1291-02 as
J 21461 to clean, .006 " diameter holes (Fig. 28).
shown in Fig. 26.
Before using the wire, hone the end until it is smooth
and free of burrs and taper the end a distance of
6. Refer to Fig. 36 and remove the spill deflector.
1/16 " with stone J 8170. Allow the wire to extend
Then lift the bushing straight out of the injector body.
1/8 " from tool J 4298-11.
7. Remove the injector body from the holding fixture.
Turn the body upside down and catch the gear
retainer and gear in your hand as they fall out of the
body.
Fig. 31 - Sealing Surfaces which may Require
Fig. 32 - Examing Sealing Surface with a
Lapping
Magnifying Glass
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