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 176 of 779
Table 4-9.
Para 4-22
Para 4-23
Para 4-24
4-22. Checking Cylinder Compression
a. General.
For instructional purposes in
this section all fuel injector nozzle and holder
assemblies will be removed and a compression
test
will
be
made
on
all cylinders. If
troubleshooting indicates that only one cylinder
requires a compression check, it may be done by
rem oving the nozzle from
the questionable
cylinder.
Warning;
When only one cylinder is checked,
there is the possibility of the engine firing on the
other cylinders when compression check is being
made. To prevent engine firing, remove all
nozzles then check cylinder compression. Unless
all nozzles are removed, the engine motoring rpm
will be below desired cylinder checking rpm.
b. Starting Engine.
Check the vehicle
batteries to assure full charge and replace if
necessary.
Refer to the pertinent operator’s
manual for engine starting procedures. Start
engine
and allow engine
to reach normal
operating temperature and then stop engine. Cut
off fuel supply so engine will not deliver fuel
while performing compression test.
c. Compression
Test.
Remove the fuel
injector nozzle and holder assemblies from each
cylinder (para 4-17). Install the compression
checking adapter and compression gage (figs. 4-
184 and 4-185) and motor engine with the
starter motor. Crank engine several seconds, or
until compression
gage
reaches
maximum
reading. Cylinder compression pressure should
be between 330 and 480 psi. High cylinder
pressures are caused by combustion of lubrica-
ting oil in the engine combustion chamber. If this
occurs, allow combustion gases to escape prior to
taking compression reading.
Install
1. Position new fuel injectc r nozzle gasket (A) on end of
compression adapter - 4!’10-795-7961. Apply a light
coating of grease
on
gasket so it adheres to adapter
when installed in cylinder.
Note.
Be sure gasket is installed with open
face toward adapter.
2.
Install adapter (B) into fuel injector nozzle holder
opening and tighten securely using fixed open end
wrench - 5120-871-7198
Remove
1. Remove adapter (B) frc m fuel injector nozzle holder
opening using fixed open end wrench -5120-871-7198
as shown in figure 4-16$.
2. Remove and discard gasket (A).
Figure 4-184. Installing or removing compres-
sion adapter—4910-795-7961 (cylinder
compress:ion test).
4-94
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