Cleaning. - TM-9-2815-200-350168

b. Cleaning.

(2) Valve stop spacers. Inspect the lapped

Note. D O not remove carbon from the valve,

sealing surfaces on the ends of the valve stop

(K-2, figure 4-170), or inner surface of nozzle

s p a c e r (L) for scratches, discoloration, and

body (K-1 )with a sharp tool, abrasive material, or

cracks. Inspect the area around the center hole

s t e e l wire brush, a s these implements and

o n the nozzle end for evidence of wear and

materials will severely damage the highly

pounding by the nozzle valve. Maximum

polished surfaces.

allowable depth of wear or pounding at this area

is 0.003-inch. Inspect drilled passages in spacer

(1) Fuel injector nozzle assembly. S o a k

n o z z l e body in carbon removing solvent to

for obstructions.

remove major carbon d e p o s i t s . Remaining

(3) Adjusting spring and spring seats.

carbon deposits should be removed using a soft

I n s p e c t the nozzle opening pressure adjusting

cloth or felt pad and mutton tallow. A piece of

spring (N) and spring upper and lower seats (D

soft wood, soaked in oil may also be used as a

and M) for cracks and evidence of wear.

carbon remover.

(4) Holder spring. Inspect holder spring (P)

(2) Nozzle body spray orifices. C l e a n

for cracks, and for evidence of discoloration due

carbon from the orifices of the nozzle body by

to excessive heat. Inspect free length of holder

s o a k i n g nozzle body in a carbon removing

spring. Limit should be from 1.403 to 1.409-inch

solvent only. Do not attempt to clean orifices

w h e n the new copper gasket, FSN 5310-861-

with cleaning wire as this method will distort

1406, is used. If the old copper-asbestos gasket is

nozzle orifices and also may block opening due to

used the limit should be 1.407 to 1.409-inch.

wire breakage. It is difficult and often impossible

(5) Holder body. Inspect the holder body

to remove broken pieces of wire.

(A) for cracks, burs, nicks, and raised metal.

(3) Fuel injector h o l d e r and associated

Inspect lapped sealing surface for scratches and

parts. Clean all parts thoroughly. Be sure hands

d i s c o l o r a t i o n . Inspect the threaded area and

are kept free from accumulation of grease which

t a p p e d openings f o r s t r i p p e d o r d a m a g e d

will cause collection of dust and grit on parts.

threads.

Cover or wrap all parts after cleaning to protect

(6) Nozzle cap nut. Inspect the nozzle cap

them from dirt accumulation.

nut (J) for nicks, burs, raised metal surfaces, and

c. Inspection.

for cracks due to overheating. Inspect threaded

area inside nut for stripped or damaged threads.

(1) Nozzle body and valve. Inspect seat of

nozzle valve (K-2. fig. 4-170) for evidence of

Inspect the gasket area on end of nut for deep

wear, distortion of the valve seat due to pound-

scratches.

ing, d i s c o l o r a t i o n due to overheating, and

( 7 ) Nozzle retainer. Inspect the nozzle

retainer (F) for cracks, nicks, burs, and raised

pitting. Inspect the valve stem between seal and

shoulder for scratches and discoloration. Check

metal, and for rounding of the hexagon nut area.

fit of valve in nozzle body by lifting the valve

Inspect threaded area for stripped or damaged

about one-third of its length out of the body. The

threads,

valve should slide back to its seat without aid

(8) Fuel injector tube connector. Inspect the

when the assembly is held at a 45 degree angle.

fuel injector tube connector(Q) for cracks and for

Mark sticking assemblies for repair. Inspect the

s t r i p p e d or damaged threads.

eight spray orifices in the nozzle body tip and the

d. Repair.

drilled passage in the body for freedom of ob-

(1) Nozzle body and valve.

structions, I n s p e c t lapped sealing surface of

(a) Replace nozzle body (K-1, figure 4-

v a l v e body for scratches, discoloration, and

170) and nozzle valve (K-2) when body seat or

cracks. Inspect nozzle body valve seat, using a

valve seat is badly worn, pounded, or pitted, or

strong light and a magnifying glass (5 to 7 power

when nozzle does not conform to spray pattern

magnification

minimum)

for

scratches,

l i m i t s specified in paragraph 4-17c(3). Minor

d i s c o l o r a t i o n , wear, pitting, and evidence of

discoloration or imperfections of body and valve

pounding.

seat can be cleaned up by lapping the valve into

Note. An otoscope, such as used by

the body. Clamp valve by its stem in jaws of

physicians for examination of the inner ear, is

rotating chuck. Place a very minute quantity of

well suited for this purpose.

fine lapping compound on tip of valve. Slide

4-86