TM10-4320-315-24
4-3. MAINTENANCE OF FUEL INJECTORS
This task covers:
a.
Disassembly
c.
Assembly
b.
Repair
d.
Test
INITIAL SETUP:
Tools
General Safety Instructions
General Mechanics Tool Kit
Item 1, Appendix B)
WARNING
Materials/Parts
Diesel fuel is flammable. Keep sparks, cigarettes,
and open flame away from fuel system components
Fuel (Item 9, Appendix C)
while working on engine.
Equipment Conditions
Fuel injectors removed (para. 2-50).
a.
DISASSEMBLE. (Figure 4-1)
(1)
Remove injection cap (1) from nozzle holder (2).
(2)
Remove nozzle assembly (3), intermediate piece (4), plunger (5), spring (6), and shims (7).
b.
INSPECT.
(1)
Wash all parts with clean diesel fuel.
(2)
Inspect intermediate piece for scratches, burrs, or wear on the seating surfaces. Replace damaged
intermediate piece.
CAUTION
Do not touch needle seating surface. Needle can be damaged.
(3)
Remove needle (8) from nozzle assembly (3).
(4)
Insert needle (8) into nozzle assembly (3). Hold nozzle assembly vertical. Allow needle (8) to slide
slowly, under its own weight, down on seat. If needle does not seat, replace nozzle assembly.
c.
ASSEMBLE.
(1)
Insert shims (7) in the nozzle holder (2).
(2)
Refer to injector test (task d). Add or subtract shims (8) as necessary to obtain correct opening
pressure.
(3)
Insert spring (6) in nozzle holder (2).
(4)
Install plunger (5) on spring (6) with beveled side of plunger away from spring.
4-2
