The former and new check valve and check valve cage are not separately interchangeable in a former
injector (Fig. 39).
5. Insert the spring seat in the valve spring, then insert the assembly into the spring cage, spring seat first.
Install a new spring seat (Fig. 39) in a former injector if a new design spray tip assembly is used.
6. Place the spring cage, spring seat, and valve spring assembly (valve spring down) on top of the check valve
When installing a new spray tip assembly in a former injector, a new valve spring seat must also be
installed. The current needle valve has a shorter quill.
7. Insert the needle valve, tapered end down, inside of the spray tip (Fig. 2). Then place the spray tip and
needle valve on top of the spring cage with the quill end of the needle valve in the hole in the spring cage.
8. Lubricate the threads in the injector nut and carefully thread the nut on the injector body by hand. Rotate
the spray tip between your thumb and first finger while threading the nut on the injector body (Fig. 40). Tighten
the nut as tight as possible by hand. At this point, there should be sufficient force on the spray tip to make it
impossible to turn with your fingers.
9. Use socket J 4983-01 and a torque wrench to tighten the injector nut to 75-85 lb ft (102-115 Nm) torque (Fig.
10. After assembling a fuel injector, always check the area between the nut and the body. If the seal is still
visible after the nut is assembled, try another nut which may allow assembly on the body without extruding the
seal and forcing it out of the body-nut crevice.
Do not exceed the specified torque. Otherwise, the nut may be stretched and result in improper sealing
of the lapped surfaces in a subsequent injector overhaul.
Assemble Plunger and Follower
1. Refer to Fig. 38 and slide the head of the plunger into the follower.
2. Invert the injector in the assembly fixture, filter cap end up, and push the rack all the way in. Then place the
follower spring on the injector body.
3. Refer to Fig. 42 and place the stop pin on the injector body so that the follower spring rests on the narrow
flange of the stop pin. Then align the slot in the follower with the stop pin hole in the injector body. Next align
the flat side of the plunger with the slot in the follower. Then insert the free end of the plunger in the injector
body. Press down on the follower and at the same time press the stop pin into position. When in place, the
spring will hold the stop pin in position.