Cessna SKYMASTER 336 1964 - TROUBLE SHOOTING

CESSNA AIRCRAFT COMPANY
MODEL 336
SERVICE MANUAL
NOTE:
There are
certain general
precautions and
rules concerning
the fuel system,
which should
be observed
when
performing the operations
and procedures
in this section.
These are as
follows:
WARNING:
REMOVE ALL
IGNITION SOURCES FROM THE
AIRPLANE AND VAPOR HAZARD AREA.
SOME TYPICAL
EXAMPLES
OF IGNITION SOURCES
ARE STATIC
ELECTRICITY,
ELECTRICAL
POWERED EQUIPMENT (TOOLS
OR ELECTRONIC TEST EQUIPMENT
-
BOTH
INSTALLED ON
THE AIRPLANE
AND GROUND SUPPORT
EQUIPMENT),
SMOKING AND SPARKS FROM METAL TOOLS.
WARNING: OBSERVE
ALL STANDARD FUEL SYSTEM
FIRE AND SAFETY PRACTICES.
a. During all fueling, defueling, tank purging,
and tank repairing or disassembly, ground
the airplane to a
suitable ground stake.
b. Residual fuel draining
from lines and
hoses constitutes a
fire hazard. Use caution
to prevent the
accumulation of fuel
when lines or hoses are
disconnected.
c. Throughout the
fuel system use a thread
lubricant of graphite-petrolatum
(Spec.
MIL-T-5544, or
equivalent)
only if necessary.
Anti-seize compound
(Spec. JAN-A-660,
or equivalent) may
be used to
seal a leaking connection.
Apply sparingly
to male fittings only,
omitting the first two
threads. Always be
sure that a compound,
the residue
from a previously use
compound, or any
other foreign material
cannot enter
the fuel system.
11-3 TROUBLE
SHOOTING.
NOTE: Use
this chart in conjunction
with
the engine and
fuel injection
trouble shooting
charts in Section
10.
PROBABLE CAUSE ISOLATION
PROCEDURE
NO FUEL FLOW
TO ENGINE-DRIVEN
PUMP.
Selector valve
not turned
on.
Fuel tanks empty.
Fuel line disconnected or broken.
Selector
valve not rigged
properly.
Fuel cell
outlet screens
plugged.
Unserviceable selector valve.
Plugged
fuel strainer.
Unserviceable
bypass valve
in
electric
fuel
pump.
Fuel line plugged.
Check position
of selector
valve.
Check
fuel
quantity.
Inspect fuel lines.
Check
selector
valve is in detent.
Disconnect
fuel lines
from auxiliary
or
sump
tank outlets. No
flow indicates
plugged
screens.
Disconnect inlet and outlet lines from
valve. With
valve in detent,
fuel should
flow from
inlet line but not
through valve.
Inspect strainer.
Disconnect inlet and outlet lines from
pump. If fuel flow
from inlet line
but not
through valve,
it is unserviceable.
Disconnect
at fuel pump inlet.
No flow
indicates plugged line.
Turn selector valve on.
Service with proper grade and
amount of fuel.
Connect
or repair fuel
lines.
Re-rig
selector
valve.
Remove and
clean screens
and
flush out fuel cells.
Remove
and repair
or replace
selector valve.
Remove
and clean
strainer
and
screen.
Repair pump. Replace bypass
valve.
Disconnect lines as necessary to
locate obstructions, then clean.
FUEL STARVATION AFTER STARTING
Partial fuel flow from the preceding
causes.
Malfunction of engine-driven fuel
pump or
fuel injection
system.
Fuel vents plugged.
Use
the preceding
isolation procedure,
checking for sufficient rate of flow.
Refer to
Section
10.
Check
per paragraphs
11-3 and 11-48.
© Cessna Aircraft Company
Use the
preceding remedies.
Refer to Section 10.
See
paragraphs
11-3 and 11-48.
Change 2
Jan 5/2004
REMEDY
11-2