Cessna Skyhawk 172N Pilot Operating Handbook page 234

(5) NOSE
(1) Reservoir Tank Quick Drain Valve - DRAIN at least a
cupful of fuel (using sampler cup) from valve to check
for water, sediment and proper fuel grade (Diesel or
JET-A1) before each flight and after each refueling. If
water is observed, take further samples until clear and
then gently rock wings and lower tail to the ground to
move any additional contaminants to the sampling
point. Take repeated samples until all contamination
has been removed.
Note:
(2) Before first flight of the day and after each refueling -
DRAIN the Fuel Strainer Quick Drain Valve with the
sampler cup to remove water and sediment from the
screen. Ensure that the screen drain is properly closed
again. If water is discovered, there might be even more
water in the fuel system. Therefore, take further
samples from fuel strainer and the tank sumps.
Note:
(3) Engine Oil Dipstick/Filler Cap:
a) Oil level - CHECK
b) Dipstick/filler cap - SECURE
Do not operate below the minimum dipstick indication.
(4) Engine Air and Cooling Inlets - CLEAR of obstructions
(5) Landing Light - CHECK for condition and cleanliness
(6) Propeller and Spinner - CHECK for nicks and security
(7) Gearbox Oil Level - CHECK the oil has to cover at least
half of the inspection glass
(8) Nose Wheel Strut and Tire- CHECK for proper inflation
of strut and general condition (weather checks, tread
depth and wear, etc.) of tire
Page 4-4
Issue 2
Revision 7, Jan. 2018
Reims/Cessna (F) 172 N&P
The reservoir tank drain is located in the
fuselage on the co-pilot side of the aircraft.
The fuel strainer drain is located on the left-
hand side of the firewall (flight direction).
Supplement POH
with TAE 125-02-114