2.1.4 Injector Tube
DETROIT DIESEL 53
of chips) until the lower shoulder of the
reamer contacts the injector tube (Fig. 4.).
Clean out all of the chips.
2. Remove excess stock:
With the cylinder head bottom side up,
insert the pilot of cutting tool J 5286-8 into
the small hole of the injector tube.
Place a few drops of cutting oil on the tool.
Then, using a socket and a speed handle,
remove the excess stock so that the lower
end of the injector tube is from flush to
.005" below the finished surface of the
3. Ream the bevel seat in the injector tube:
Fig. 3. - Upsetting Injector Tube
The tapered lower end of the injector tube must provide
a smooth and true seat for the lower end of the injector
Ream Injector Tube
nut to effectively seal the cylinder pressures and
properly position the injector tip in the combustion
After an injector tube has been installed in a cylinder
chamber. Therefore, to determine the amount of stock
head, it must be finished in three operations: First, hand
that must be reamed from the bevel seat of the tube, the
reamed, as shown in Fig. 4, to receive the injector body
injector assembly should be
nut and spray tip; second, spot-faced to remove excess
stock at the lower end of the injector tube; and third,
hand reamed, as shown in Fig. 5, to provide a good
seating surface for the bevel or the lower end of the
injector nut. Reaming must be done carefully and
without undue force or speed so as to avoid cutting
through the thin wall of the injector tube.
NOTE: The reamer should be turned
in a clockwise direction only, both
withdrawing the reamer, because
movement in the opposite direction
will dull the cutting edges of the
1. Ream the injector tube for the injector nut and spray
tip. With the cylinder head right side up and the injector
tube free from dirt, proceed with the first reaming
operation as follows:
Place a few drops of light cutting oil on the
reamer flutes, then carefully position the reamer
Fig. 4. - Reaming Injector Tube for Injector
J 22525-1 in the injector tube.
Body and Spray Tip
Turn the reamer in a clockwise direction
(withdrawing the retainer frequently for removal
1970 General Motors Corp.