2.1.1 Fuel Injector
DETROIT DIESAL 53
NOTE: Whenever a fuel injector is
disassembled) discard the filters and
gaskets and replace with new filters
and gaskets. In the offset injector, a
filter is used in the inlet side only.
No filter is required in the outlet side
(Fig. 34.).
2. Compress the follower spring as shown in Fig. 11..
Then raise the spring above the stop pin with a screw
Fig. 31. - Sealing Surfaces which may Require
driver and withdraw the pin. Allow the spring to rise
Lapping
gradually.
on which to place the injector parts after cleaning and
3. Refer to Fig. 24.. and remove the plunger follower,
inspection.
plunger and spring as an assembly.
Wash all of the parts with clean fuel oil or a suitable
4. Invert the fixture and, using socket J 4983-01,
cleaning solvent and dry them with clean, filtered
loosen the nut on the injector body (Fig. 25.).
compressed air. Do not use waste or rags for cleaning
purposes. Clean out all of the passages, drilled holes
5. Lift the injector nut straight up, being careful not to
and slots in all of the injector parts.
dislodge the spray tip and valve parts. Remove. the
spray tip and valve parts from the bushing and place
Carbon on the inside of the spray tip may be loosened
them in a clean receptacle until ready for assembly.
for easy removal by soaking for approximately 15
minutes in a suitable solution prior to the external
When an injector has been in use for some time, the
cleaning and buffing operation. Methyl Ethyl Keytone J
spray tip, even though clean on the outside, may not be
8257 solution is recommended for this purpose.
pushed readily from the nut with the fingers. In this
event, support the nut on a wood block and drive the tip
Clean the spray tip with tool J 9464-01 (Fig. 27.).
down through the nut, using tool J-1291-02 as shown in
Fig. 26.
CAUTION: Care must be exercised
when inserting the carbon remover J
6. Refer to Fig. 36. and remove the spill deflector.
Then lift the bushing straight out of the injector body.
9464-01 in the spray tip to avoid
contacting the needle valve seat in
7. Remove the injector body from the holding fixture.
the tip.
Turn the body upside down and catch the gear retainer
and gear in your hand as they fall out of the body.
Wash the tip in fuel oil and dry it with compressed air.
Clean the spray tip orifices with pin vise J 4298-1 and
8. Withdraw the injector control rack from the injector
the proper size spray tip cleaning wire. Use wire
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
Fig. 32. - Examing Sealing Surface with a
Magnifying Glass
Fig. 30. - Cleaning Injector Nut Spray Tip Seat -
1972 General Motors Corp.
Page 14
