Piper Navajo PA-31 Service Manual page 53

PIPER NAVAJO SERVICE MANUAL
2-51. OIL SYSTEM (ENGINE).
2-52. SERVICING OIL SYSTEM. The engine oil level should be checked before each flight and changed
after each 50 hours of engine operation. During oil change, the oil suction screen should be removed and
cleaned and the oil filter element replaced. Intervals between oil changes can be increased as much as 100%
provided the element is replaced each 50 hours of operation. Detailed instructions for servicing the
lubrication system may be found in Section VIII.
2-53. FILLING OIL SUMP. The oil sump should normally be filled with oil to the 12 U.S. quart mark on
the engine dipstick. The specified grade of oil may be found in the lubrication chart information or on each
engine oil filler access door. To service the engine with oil, open the quick release access door on top of the
cowl and remove the oil filler cap with dipstick.
NOTE
Oil dipsticks are marked for right and left engines. Use the correct
side of stick when checking oil level.
2-54. DRAINING OIL SUMP. To drain the oil sump provide a suitable container with a minimum capacity
of 12 quarts. Remove the engine cowl and open the oil drain valve located on the left underside of the
engine by pushing the arms of the drain up and turn counterclockwise. This will hold the drain in the open
position. It is recommended the engine be warmed to operating temperature to insure complete draining of
the old oil.
2-55. LUBRICATION.
2-56. LUBRICATION INSTRUCTIONS. Proper lubrication procedures are of immeasurable value both as
a means of prolonging the service life of the airplane and as a means of reducing the frequency of extensive
and expensive repairs. The periodic application of recommended lubricants to their relevant bearing
surfaces, as detailed in the following paragraphs, together with the observance of cleanliness, will insure the
maximum efficiency and utmost service of all moving parts. Lubrication instruction regarding the locations,
time intervals, and type of lubricants used may be found in Figures 2-13 to 2-13e. To insure the best
possible results from the application of lubricants, the following precautions should be observed:
a.
Use recommended lubricants. Where general purpose lubricating oil is specified, but unavailable,
clean engine oil may be used as a satisfactory substitute.
b. Check the components to be lubricated for evidence of excessive wear and replace them as
necessary.
c. Remove all excess lubricants from components in order to prevent the collection of dirt and sand
in abrasive quantities capable of causing excessive wear or damage to bearing surfaces.
Reissued: 10/12/79
HANDLING AND SERVICING
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