Cessna 150M - Nose Gear Shock Strut; Nose Gear Shimmy Dampener; Hydraulic Brake Systems; Cleaning

NOTE
Recommended tire pressures should be main-
tained. Especially in cold weather, remember
that any drop in temperature of the air inside
a tire causes a corresponding drop in air pres-
sure.
2-26. NOSE GEAR SHOCK STRUT. The nose gear
shock strut requires periodic checking to ascertain
that the strut is filled with hydraulic fluid and is in-
flated to the correct air pressure. To fill the nose
gear strut with hydraulic fluid and inflate with air,
proceed as follows: '
a. Remove filler valve cap and depress valve core
to completely deflate nose strut.
b. Remove filler valve from strut.
c. With nose gear strut compressed to its shortest
length, fill strut with hydraulic fluid to the bottom of
the
filler hole.
d. Raise nose of aircraft, extend and compress
strut several times to expel any entrapped air, then
lower nose of aircraft and repeat step "c".
e. With strut compressed to its shortest length,
install filler valve assembly.
f. With nose wheel off ground, inflate strut. Shock
strut pressure is listed in figure 1-1.
NOTE
The nose landing gear shock strut will nor-
mally require only a minimum amount of
service. Maintain the strut extension pres-
sure, as shown in figure 1-1. Lubricate
landing gear as shown in figure 2-5. Check
the landing gear daily for general cleanli-
ness, security of mounting, and for hydrau-
lic fluid leakage. Keep machined surfaces
wiped free of dirt and dust, using a clean
lint-free cloth saturated with MIL-H-5606
hydraulic fluid or kerosene. All surfaces
should be wiped free of excessive hydraulic
fluid.
2-27. NOSE GEAR SHIMMY DAMPENER. The
shimmy dampener should be serviced at least every
1
5
0
hours. The shimmy dampener must be filled
completely with flUid, free of entrapped air, to
serve its purpose. To service the shimmy damp-
ener, proceed as follows:
a. Remove shimmy dampener from aircraft.
b. While holding the dampener in a vertical posi-
tion with fitting end pointed downward, pull fitting
end of the dampener shaft to its limit of travel.
c. While holding dampener in this position, fill
dampener through open end of cylinder.
d. Push the shaft upward slowly to seal off the fil-
ler hole.
e. Clean dampener with solvent. Be sure to keep
the shaft protruding through the filler hole until
dampener is installed on the aircraft.
£. Install dampener on aircraft.
NOTE
Keep shimmy dampener, especially the ex-
posed portions of the dampener piston shaft,
clean to prevent collection of dust and grit
which could cut the seals in the dampener
barrel. Keep machined surfaces wiped free
of dirt and dust, using a clean lint-free cloth
saturated with MIL-H-5606 hydraulic fluid
or kerosene. All surfaces should be wiped
free of excessive hydraulic fluid.
2-28. HYDRAULIC BRAKE SYSTEMS. Check brake
master cylinders and refill with hydraulic fluid as
specified in the inspection charts. Bleed the brake
system of entrapped air whenever there is a spongy
response to the brake pedals. Refer to paragraph
5-58 for filling and bleeding the brake system.
2-29. CLEANING.
2-30. Keeping the aircraft clean is important. Be-
sides maintaining the trim appearance of the aircraft,
cleaning lessens the possibility of corrosion and
makes inspection and maintenance easier.
2-31. WINDSHIELD AND WINDOWS should be
cleaned carefully with plenty of fresh water and a
mild detergent, using the palm of the hand to feel
and dislodge any caked dirt or mud. A sponge, soft
cloth, or chamois may be used, but only as a means
of carrying water to the plastic. Rinse thoroughly,
then dry with a clean moist chamois. Do not rub the
plastiC with a dry cloth as this builds up an electro-
static charge which attracts dust. Oil and grease
may be removed by rubbing lightly with a soft cloth
moistened with Stoddard solvent.
I~AUTION\
Do not use gasoline, alcohol, benzene, acetone,
carbon tetrachloride, fire extinguisher flUid,
de-icer flUid, lacquer thinner, or glass window
cleaning spray. These solvents will soften and
craze the plastic.
After washing, the plastic windshield and windows
should be cleaned with an aircraft windshield cleaner.
Apply the cleaner with soft cloths and rub with mod-
erate pressure. Allow the cleaner to dry, then wipe
it off with soft flannel cloths. A thin, even coat of
wax, polished out by hand with soft flannel cloths,
will fill in minor scratches and help prevent further
scratching. Do not use a canvas cover on the wind-
shield or windows unless freezing rain or sleet is
anticipated since the cover may scratch the plastic
surface.
2-32. PLASTIC TRIM. The instrument panel, plas-
tic trim, and control knobs need only be wiped with
a damp cloth. Oil and grease on the control wheel
and control knobs can be removed with a cloth moist-
ened with Stoddard solvent. Volatile solvents, such
as mentioned in paragraph 2-31, must never be used
since they soften and craze the plastic.
2-33. PAINTED SURFACES. The painted exterior
surfaces of the aircraft, under normal conditions,
require a minimum of polishing and buffing. Approxi-
mately 15 days are required for acrylic or lacquer
paint to cure completely; in most cases, the curing
Change 3 2-9