TM-9-2815-200-35
ENGINE, WITH CONTAINER:TURBOSUPERCHARGED, DIESEL ,FUEL INJECTION ,90-DEGREE “V” TYPE, AIR - COOLED ,12 - CYLINDER , ASSEMBLY ;MODELS AVDS-1790-2M (2815-856-4996), AVDS-1790-2A AND AVDS-1790-2AM (2815-856-9005)
TECHNICAL MANUAL; DIRECT SUPPORT, GENERAL SUPPORT AND DEPOT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS
TM-9-2815-200-35 - Page 169 of 779
nozzle body over valve and lap valve to seat with
a very light pressure for 15 to 20 seconds at 500
to 600 rpm chuck speed. Wash body and valve
very thoroughly in clean fuel before assembly.
(b) A sticking valve can, in some in-
stances, be made to slide freely by cleaning the
valve stem with tallow and a felt pad with valve
clamped in rotating chuck. If the valve cannot be
made to slide freely, the fuel injector nozzle
assembly must be replaced.
(c) Replace nozzle body and valve
assembly when any of the spray holes or the
drilled fuel passage cannot be cleaned so that
they are free from obstructions.
(d) Replace nozzle body and valve
assembly when lapped sealing surface of body is
badly nicked, scratched, or cracked. Remove
minor scratches from sealing surface by lapping
with fine lapping compound on a smooth lapping
plate. The nozzle body must be held flat on the
lapping plate during this operation or the sealing
surface will become rounded on the edges.
(2) Valve stop spacer.
(a) Replace valve stop spacer (L) when
lapped sealing surfaces on either end are cracked,
deeply scratched, pitted, or when the area around
the center hole at nozzle end is worn or pounded
beyond 0.003-inch depth.
(b) Remove minor scratches and im-
perfections from lapped sealing areas on ends of
spacer by lapping with fine lapping compound
on a smooth lapping plate. The spacer must be
held flat against the lapping plate during this
operation or the sealing surface will become
rounded on edges.
(c) Replace valve stop spacer when
drilled fuel passages cannot be cleaned so that
they are completely free from obstructions.
(3) Adjusting spring and spring seats.
Replace nozzle
opening pressure
adjusting
spring (N) and spring upper and lower seats (D
and M ) when cracked or worn, or when nozzle
opening pressure does not meet the limits
specified in paragraph 4-17c(2).
(4) Holder spring.
Replace holder spring
(P) when cracked, broken, or when inspection
revealed discoloration due to overheating.
Replace the holder spring when it does not
conform to the dimensions detailed in para. 4-
18c(4).
(5) Holder body.
(a) Replace holder body (A) when
cracked, burred, nicked, or when threads are
stripped or damaged.
(b) Remove minor scratches and im-
perfections in lapped sealing surface of holder
body by lapping with fine lapping compound on
a smooth lapping plate. The holder and plate
must be held 90 degrees to each other. There
should be no rocking motion during lapping.
(6) Nozzle cap nut.
Replace nozzle cap nut
(J) when badly nicked, burred, or when cracks
are evident due to overheating. Replace cap nut
when threads are stripped or damaged, and
when gasket area is scratched, nicked, or burred.
(7) Nozzle retainer.
Replace nozzle retainer
(F) when cracked, badly nicked or burred or
when hexagon nut area is damaged, Replace
retainer when threads are stripped or damaged.
(8)
Fuel injector tube connector.
Replace
fuel injector tube connector (Q) when cracked or
threads are stripped or damaged.
e. Assemble and Test.
(1) Assemble.
Refer to figures 4-169 and 4-
170.
(2) Test.
Refer to paragraph 4-17c. The fuel
injector nozzle and holder assembly should be
tested whenever nozzle has been disassembled.
4-87
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