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MODEL 182 & T182 SERIES SERVICE MANUAL
g.
Pinch or close the rubber hose to sustain pres-
sure in the fuel bay.
tube to retain pressure within the cell. Loosen. but
h. Apply a soap solution to the fuel filler caps and
do not remove filler cap on opposite wing to check
inspect for leakage around the rubber seal to filler
cell crossover line. If pressure escapes from filler
neck junction, the fuel cap vent. and the fuel cap
cap, crossover line is open. Remove rubber tube
handle stem. Load the cap sideways in all directions
from end of vent line beneath the wing after comple-
by pressing on the fuel cap vent housing by hand.
tion of check.
NOTE
NOTE
No leakage is permissible.
If leaks are
Remember that a plugged vent line or bleed
present, replace
the cap with a new unit
hole can cause either fuel starvation or the
or repair in accordance with Cessna
pressurization of cells by fuel expansion.
Service Information Letter SE 80-59
Supplement #1 dated June 23 1980.-
f. Any fuel vent found plugged or restricted must
be corrected prior to returning aircraft to service.
Care must be exercised in removing the
fuel filler caps until the system has been
The fuel vent line protruding beneath the
depressurized.
wing near the wing strut must be correctly
aligned to avoid possible icing of the vent
i.
After replacement or repair of either fuel filler
tube. Dimensions are shown in figure 6.
cap, repeat the inspection.
j.
Remove the rubber hose, unplug or remove the
12-24A. ADJUSTMENT.
On aircraft serials 182-
tape from the other fuel vent, and place the fuel
66591 and on, uneven fuel flow from the integral fuel
selector in the desired position.
bays, when the aircraft fuel selector valve is posi-
tioned to feed from both fuel bays. can be caused by
12-21.
FUEL QUANTITYTRANSMITTERS.
Refer
unequal pressures in the fuel venting system. When
to Section 15 for a detailed description, operation,
uneven fuel flow is observed, the venting system may
and maintenance procedure.
be checked and unequal pressures in the system cor-
rected by using the following procedures:
12-22. FUEL VENTS.
NOTE
12-23. DESCRIPTION. A vent line is installed in
the outboard end of each fuel bay and extends over-
The following procedure should be accom-
board through the lower wing skin. The inboard end
plished during a sequence of routine flight
of the vent line extends into the fuel cell. then
operations.
Special flights for the sole
bends down and inboard. A vent valve is install-
purpose of checking and adjusting fuel
ed on the inboard end of the vent line inside the fuel
tank feed rates are not recommended.
cell, and a crossover line connects the cells together.
On aircraft equipped with long-range cells, a nylon
a. Inspect the venting system to insure the lines
vent tube is attached to the crossover line at the in-
are open, connections secure and that the system
board end of each cell. This vent tube extends into
is functioning properly.
the fuel cell, and is suspended by four hangers in the
b.
Park the aircraft on level ground and select the
top of the cell.
'both' position on the fuel selector.
Leave the air-
craft parked until the tank levels are equal or fill
12-24.
CHECKING.
Fuel vents can become plugged
both tanks.
as evidenced by field experience, and can cause fuel
c. With the fuel selector in the 'both' position, take
starvation of the engine. If the bleed hole in the vent
off and climb to an altitude where the air is smooth.
valve becomes plugged, then over pressurization can
d. Trim the aircraft for straight and level flight.
occur due to normal temperature variation. This
Make sure the aircraft is free of any 'yaw' by trim-
would usually occur then the airplane engine is not
ming the rudder to center the ball of the turn coordi-
operating.
The following procedure should be used
nator.
Cruise at the top of the green band on mani-
to check the fuel vent and bleed system.
fold pressure for a period of at least one hour.
a. Attach a rubber tube to the end of vent line be-
e. At the end of the hour and while still in straight
neath the wing.
and level flight, take note of the fuel tank levels as
b. Plug vent on opposite wing from one being tested.
indicated on the fuel gauge.
c. Slightly pressurize the cell, if air can enter the
f.
If the fuel tank levels are greater than 5 gallons
cell, the vent line is open.
apart, land the aircraft and perform the following
d. After cell is slightly pressurized, insert end of
procedure:
rubber tube into a container of water and watch for a
1. Bend the underwing vent of the tank which
continuous stream of bubbles, which indicates the
had the highest level outboard 1/4".
bleed hole in valve assembly is open and relieving
2.
Bend the underwing vent of the tank which
pressure.
had the lowest level inboard 1/4", providing the vent
e. After completion of step "c", blow into tube
is not squarely behind the strut. Repeat the first
again to slightly pressurize the cell. Crimp rubber
five steps.
12-16
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