Cessna Skyhawk 172N Pilot Operating Handbook page 154

CESSNA SECTION 8
MODEL 172N HANDLING, SERVICE
&
MAINTENANCE
CAPACITY OF ENGINE SUMP -- 6 Quarts.
Do not operate on less than 4 quarts. For extended flight, fill to 6 quarts.
These quantities refer to oil dipstick level readings. During oil and oil
filter changes, one additional quart is required when the filter is
changed.
OIL AND OIL FILTER CHANGE -­
After the first 25 hours of operation, drain the engine oil sump and oil
cooler and clean the oil pressure screen. If an oil filter is installed,
change the filter at this time. Refill sump with straight mineral oil and
use until a total of 50 hours has accumulated or oil consumption has
stabilized; then change to dispersant oiL
On airplanes not equipped with an oil filter, drain the engine oil sump
and oil cooler and clean the oil pressure screen each 50 hours thereaf­
ter.
On airplanes which have an oil filter, drain the engine oil sump and oil
cooler and change the oil filter again at the first 50 hours; thereafter,
the oil and filter change interval may be extended to 100-hour inter­
vals.
Change engine oil at least every 6 months even though less than the
recommended hours have accumulated. Reduce intervals for pro­
longed operation in dusty areas, cold climates, or when short flights
and long idle periods result in sludging conditions.
NOTE
During the first 25-hour oil and filter change, a general
inspection of the overall engine compartment is required.
Items which are not normally checked during a preflight
inspection should be given special attention. Hoses, metal
lines and fittings should be inspected for signs of oil and
fuel leaks, and Checked for abrasions, chafing, security,
proper routing and support, and evidence of deterioration.
Inspect the intake and exhaust systems for cracks, evi­
dence of leakage, and security of attachment. Engine
controls and linkages should be checked for freedom of
movement through their full range, security of attachment
and evidence of wear. Inspect wiring for security, chafing,
burning, defective insulation, loose or broken terminals,
heat deterioration, and corroded terminals. Check the
alternator belt in accordance with Service Manual instruc­
tions, and retighten
if
necessary. A periodic check of these
items during subsequent servicing operations is recom­
mended.
1 July 1978
8-11