Piper Comanche PA-24 Service Manual page 605

PIPER COMANCHE SERVICE MANUAL
7C-68. Oil Cooler.
a. When conducting a routine engine inspection, the oil cooler(s), lines and fittings should be checked
for the following:
I. Oil cooler line attachments should be examined to be certain that all are tight and there is no
indication of cross·threading. (See c, below, for oil line torque.)
2. Oil lines must have adequate clearance and be properly aligned.
3. 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 indication of high oil temperatures or during a 500 hour inspection,
the oil cooler should be removed, cleaned and checked for damaged fins and cells. When replacing the cooler,
properly align and do not over tighten the mounting bolts so that the cooler would be damaged. While the oil
cooler is removed, the oil lines should be disconnected and flushed.
c. 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 3/4 tum. Do not over
torque.
d. Should oil continue to leak. it may be necessary to replace the seal rings. Also remove the
compression nuts and inspect the line ends in the area of the swaged ferrules for collapsed tubing. This
condition may be observed by looking into the tubing ends. Should the tubing show indications that it is
collapsed and new seal rings and proper torque does not stop leakage, the oil lines should be replaced. Also
inspect the surfaces of the mating fittings for damage.
Revised: 8115198
2H23
POWER PLANT
PA·24·260 TURBO