Thrush Aircraft S2R-R1340 Maintenance Manual page 123

THRUSH AIRCRAFT, INC – MODEL S2R R1340
PROBLEM
No fuel flow to
engine. Fuel line plugged.
(Continued)
Fuel starvation Partial fuel flow from the
after starting. preceding causes.
Malfunction of engine-
driven fuel pump.
Fuel vents plugged.
No fuel flow
Defective electric
when auxiliary
auxiliary fuel pump
pump is turned
switch.
on.
Open or defective
circuit breaker.
Loose connections or
open circuit.
Defective auxiliary fuel
pump.
Defective engine-driven
fuel pump by-pass
valve.
Fuel flow
indicator
No voltage to indicator.
inoperative.
(Optional Equip)
Fuel flow
Indicator comes
Bad wires to transducer
on but will not
or defective transducer.
show fuel flow.
(Optional Equip)
Effective: 01/01/08
AIRCRAFT MAINTENANCE MANUAL
PROBABLE CAUSE REMEDY
Starting at fuel pump inlet, disconnect
fuel lines successively until plugged line
is located. Clean out or replace fuel line.
Use the preceding isolation procedures,
checking for sufficient rate of flow. Using
the preceding remedies.
Check pump outlet during starting.
Replace fuel pump. See Section IV.
Check ram air inlet for blockage.
Pressure check each vent line. Clean or
replace vent line.
Check continuity of switch. Replace
defective switch.
Check visually. If not open, check
continuity. Reset. Replace if defective.
Check connections and wiring. Tighten
connections; repair or replace wiring.
Disconnect outlet line. With proper fuel
supply to pump, fuel under pressure
should flow from outlet. Replace
defective pump.
Check pump outlet during starting. See
Section IV and replace fuel pump if by-
pass valve is defective or installed
backwards.
Check voltage and ground wire. If
voltage is present and ground is good,
replace indicator, maintaining the same K
factor.
To check transducer, remove four screws
holding wire housing to flow vane
housing. With battery power on, pass
screwdriver back and forth over wire
housing pickups. You should get a
reading on indicator. If no reading,
replace units.
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