Piper Comanche PA-24 Service Manual page 508

PIPER COMANCHE SERVICE MANUAL
With the engine thoroughly warmed upand running at a maximum of
2200
RPM. observe the read.'
on the oil pressure gauge If the pressure is above 90 psi. stop engine. loosen the adjusting locknut: and b
off the adJusting screw one or two full turns. Tighten locknut and retest If pressure
IS
too
10"
turn adjuslI
screw further into the relief \al\e plug. thereby increasing the tension on the relief \al,e spring When the
\al\e has been satisfactorily adjusted. tighten the locknut and lock wire the crown nut to the drilled ear
projecting from the \alw mounting boss
7A-85 Oil Screen. The oil screens are the pressure screen. located in a dome shaped housing. above and
between the magnetos and the suction
scre~n
located in
~he
lower aft section of the sump
Thes~
screens
should be cleaned at each oil change to remove any accumulation of sludge and to examine for metal filings
or chips. If metal particles are found in the oil screens. the engine should be examined for internal damge
a To remove the pressure screen. remove oil temperature electrical lead or the temperature bulb and
the cap screws securing the housing )l;ote the location of the screws as the round fillister head scre". if
installed. must be returned to upper right corner of the housing If the fillister head screw is not reinstalled
in the same hole from .... hich it "as removed. it is pO>sible to crack the mounting flange of the vacuum pump
b With the housing and screen removed. clean and inspect both items. check the matir· 'Jrlace of
the housing and accessory case for gasket panicles
c. Insert the screw into the housing so that the screw fits flush with the housing base Lsing a ne"
gasket. secure the housing to its mounting pad and torque cap screws to 75 inch pounds
d The suction screen is removed from the sump by remO\ ing the hex head plug at the 100\er aft part
of the sump Clean and inspect the screen and gasket. replace the gasket if owr compressed or damaged
Insert the screen fully into the sump. install gasket and plug. Safety the plug
7 A-So Oil Cooler.
a When conducting a routine engine inspection. the oil cooler(s). lines and fittings should be chect·
for the follo"ing
I Oil cooler line attachments should be examined to be cenain that all are tight and there
IS
indication of crmsthreading (See C for oil line torque.)
2 Oil lines must have adequate clearance and be properly aligned
J
Oil line supports should be tight. properly positioned and if worn should be replaced
4 Oil cooler should be checked for leakage or distorted. cells
5 Cooling fins should be clean and undamaged.
b During each engine overhaul. at indications of high oil temperatures or during a 500 hOllr
inspection. the oil cooler should be removed. cleaned and checked for damaged fins and cells "'''hen
replacing the cooler. properl) align and do not O\er tighten the mounting bolts so that the cooler \\ould be
damaeed While the oil cooler is remo\·ed. the oil lines should be disconnected and flushed
; If it is found that oil is leaking around the line compression nuts. check that the nuts are tightened
to 125 inch pound wet torque or the nut may be backed off. retightened finger tight. plus a J 4 turn Do
not
O\t'T
torque.
d Should oil continue to leak. it may be necessary to replace the seal rings Also remme the
compression nulS and inspect the line ends in the area of the swagged ferrules for collapsed tubing This
condition may bc observed by looking into the tubing ends. Should the tubing show indications that It is
collapsed and nc\\ seal rings and proper torque doe, not stop leakage. the oil lines should be replaced Also
inspect the ,urfaces of the mating fittings for damage
ISSl"EO: 8/18/72
2E6
POWER Pl..e