DETROIT DIESEL 53
Fuel Injector 2.1.1
J 21461 to clean .006 " diameter holes (Fig. 28.).
ring. Clean up the opposite side of the ring in the same
Before using the wire, hone the end until it is smooth
and free of burrs and taper the end a distance of 1/16"
Carefully insert a .375 " diameter straight fluted reamer
with stone J 8170. Allow the wire to extend 1/8 " from
inside the ring bore in the injector body. Turn the
tool J 4198-1.
reamer in a clockwise direction and remove any burrs
inside the ring bore. Then wash the injector body in
The exterior surface of an injector spray tip may be
clean fuel oil and dry it with compressed air.
cleaned by using a brass wire buffing wheel, tool J 7944.
To obtain a good polishing effect and longer brush life,
Carefully insert carbon remover tool J 9418-1 in the
the buffing wheel should be installed on a motor that
injector nut. Turn it in a clockwise direction to remove
turns the wheel at approximately 3000 rpm.
the carbon deposits on the flat spray tip seat as shown
in Fig. 30. Remove the carbon deposits from the lower
A convenient method of holding the spray tip while
end of the injector nut with carbon remover J 9418-5,
cleaning and polishing is to place the tip over the drill
(Fig. 30.) in the same manner. Use care to prevent
end of the spray tip cleaner tool J 1243 and hold the
removing any metal or setting up burrs on the spray tip
body of the tip against the buffing wheel. In this way,
the spray tip is rotated while being buffed.
Wash the injector nut in clean fuel oil and dry it with
compressed air. Carbon deposits on the spray tip
CAUTION: Do not buff excessively.
seating surfaces of the injector nut will result in poor
Do not use a steel wire buffing wheel
sealing and consequent fuel leakage around the spray
or the spray tip holes may be
When handling the injector plunger, do not touch the
When the body of the spray tip is clean, lightly buff the
finished plunger surfaces with your fingers. Wash the
tip end in the same manner. This cleans the spray tip
plunger and bushing with clean fuel oil and dry them
orifice area and will not plug the orifices.
with compressed air. Be sure the high pressure bleed
hole in the side of the bushing is not plugged. If this
Wash the spray tip in clean fuel oil and dry it with
hole is plugged, fuel leakage will occur at the upper end
of the bushing where it will drain out of the injector body
vent and rack holes, during engine operation, causing a
Clean and brush all of the passages in the injector body,
serious oil dilution problem. Keep the plunger and
using fuel hole cleaning brush J 8152 and rack hole
bushing together as they are mated parts.
cleaning brush J 8150. Blow out the passages and dry
them with compressed air.
Carefully insert reamer J 21089 in the injector body (Fig.
29.). Turn it in a clockwise direction a few turns then
remove the reamer and check the face of the ring for
reamer contact over the entire face of the ring. If
necessary, repeat the reaming procedure until the
reamer does make contact with the entire face of the
Fig. 34. - Location of Filter in Injector Body
Fig. 33. - Lapping Spray Tip on Lapping Blocks
1972 General Motors Corp.
SEC. 2.1.1 Page 15