Fuel Injector Maintenance; Fuel Injector Lubrication; Fuel Injector Removal; Preparation Of Fuel Injector For Shipping - Piper PA-24 Comanche Service Manual

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PIPER COMANCHE SERVICE MANUAL
7A-H.
Fuellnjee:tor.
i
A·'
S. Fuellnjel:tor Maintenance.
a. In aencn.l. little attention is required between injector overllauis. However. it is recommended that
the foilowitll items be checked during periodic: inspection of the enpne.
1.
Check tightnas and lock of all nud and screws which fasten the injector to the e"line.
Z. Check ail fuel lines for tightness and evidence of
It&kase.
A sliJht fuel stain adjacent to the air
bleed noules
is
not cause for concern.
3. Check throttle and mixture control rods and levers,for tiJbmess and lock.
4. Remove and clean the injector fuel inlet srraincr
at
the
(Int
Z5 hour iNpection and each 50
hour inspeCtion thereafter. Damaged strainer "0" rinp should be replaced. Torque strainer to 65·10 inc:h
pounds.
b. Tests prove that .asoline which becomes stale due to prolonccd stOnce absorbs oxygen rapidly.
This stale OXIdized gasoline acquires a very distinctive odor similar to varnish. causes rapid deterioration of
synthetic rubber pans. and
also
forms a JWTImy deposit on the intcma.l meta! parts. This condition.
however. does not occur during normal operation of the injeCtor where fresh fuel
is
being constantly
circulated.
i.0\-'6. Lubrication
Of Fucllnjec:tor.
a. There is
ye~
little need for lubrication "f the injector in the field bcnveen regular overhauls.
However, the clevis pIns used in connection with the thronle and manual mixture ecnerol tevers should be
checked for freedom of movement and lubricated, if necessary.
b. Place a drop of enllne pde oil on the end of the thronle shaft in such a manner that it can work
into the throttle shaft buShings.
iA-.5i. Removal Of Fuel Injector.
a.
Remove the lower cowling as described in puaJl'aphs 7 A·S or 7A-8.
b. Disconnect the throttle and mIxture conttol cables at the injector ueie,
c. Disconnect fuel lines at Injector unit.
d. Remove the Injector from the engine sump by removing pa1locknutS, nuts and washers.
e. Cat safety
wire
.1nli remove bolts attaciung the air box to the injector unit.
iA-S8. Preparation Of Fuel Injector For Shippi",. Any unit taken
OUt
of service. or unitS being returned
for overhaul. must be flushed with preserving oil (SpecIfication
~IL-o~81.
Grade 1010),
USln!
the
tollowlng procedures:
a.
Remove plugs and drain ail fuel from the injector. If available. apply 10 to IS psi air pressure to
tne fuei Inlet until all fuel is discnarged from the injector.
b. Replace plugs and
appl~'
flushing all filtered through a 10-micron tilter
3t
13-15 psi to the injector
fuel inlet until all is discharged from the outlet.
c. Repiace fuel inlet shIpping plug.
POWER PLANT
ISSUED: i/18f72
2
013