(3)
Make sure the fuel quantity in tank No. 1 is between 70 and 80% full and center tank is more than 10% full.
B. Test Fuel Scavenge System
(1) On P5 panel, put the tank No. 1 FWD boost pump switch to ON.
(a)
Make sure that no fuel flows from center tank to tank No. 1 (both fuel quantity indicators remain constant).
(b)
To operate any of the fuel boost pumps, you must be in the flight compartment to continuously monitor the fuel quantity and the low pressure indication in the fuel tank.
WARNING: DO NOT OPERATE ANY FUEL BOOST PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. FUEL VAPORS IN THE TANK MAY IGNITE AND CAUSE A FIRE OR EXPLOSION.
1) Immediately put the applicable fuel boost pump switch(es) to OFF if the LOW PRESSURE light comes on and stays on.
NOTE: When defueling or transferring fuel with minimum backpressure to the pumps, it is possible for the low pressure light(s) to be on. In this case, monitor the tank quantity and put the pump switch(es) to OFF if the tank quantity is not changing.
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(2)
Put the L CTR and R CTR tank boost pump switches to ON.
(3)
Put the L CTR tank boost pump switch to OFF.
(a) Make sure that no fuel flows from the center tank to tank No. 1 (both fuel quantity indicators remain constant).
(4)
Put the L CTR tank boost pump switch to ON.
(5)
Put the R CTR tank boost pump switch to OFF.
(a) Make sure that no fuel flows from the center tank to tank No. 1 (both fuel quantity indicators remain constant).
(6)
Put the L CTR tank boost pump switch to OFF.
(a) Make sure there is normal fuel flow from the center tank to tank No. 1 (tank No. 1 indicator increases while center tank indicator decreases).
(7)
After 20 ±1 minute, make sure the fuel flow from the center tank to tank No. 1 has stopped.
C. Put the Airplane Back to Its Usual Condition
(1)
Put the tank No. 1 FWD boost pump switch to OFF.
(2)
Remove electrical power if it is not necessary (AMM 24-22-0/201).
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FUEL SCAVENGE JET PUMP - REMOVAL/INSTALLATION
EFFECTIVITY
AIRPLANES WITH CENTER TANK FUEL SCAVENGE SYSTEM
1. General
A. The fuel scavenge jet pump is located inside tank No. 1 and requires defueling of the tank to gain access. It is also necessary to extend leading edge flaps to gain access to the attaching hardware.
2. Equipment and Material
A. Aliphatic Naphtha - TT-N-95
B. Leading Edge Flap Actuator Locks - F80048-36
3. Prepare Fuel Scavenge Jet Pump for Removal (Fig. 401)
A. Extend leading edge flaps and install actuator locks (Ref 27-81-0, MP)
WARNING: REFER TO 27-81-0, MP FOR LOCK INSTALLATION PROCEDURE. FLAPS ARE FAST ACTING AND CAN CAUSE SERIOUS INJURY TO PERSONNEL.
B. Defuel and purge tank No. 1 (Ref 28-23-0, 28-10-0, MP).
WARNING: DO NOT COMPROMISE THE SAFETY PRECAUTIONS GIVEN FOR PURGING AND FUEL TANK ENTRY.
C. Remove access panel (Ref 28-11-11, R/I).
4. Remove Fuel Scavenge Jet Pump (Fig. 401)
A. Remove nut and washer securing pump to front spar.
B. Gain access in tank No. 1.
C. Disconnect fuel lines and remove pump. Discard O-ring.
5. Install Fuel Scavenge Jet Pump (Fig. 401)
A. Clean O-ring groove in jet pump body and tank No. 1 mating surface with naphtha, and wipe dry with lint free cloth.
B. Install new O-ring, lightly lubricated with fuel, into groove in jet pump.
C. Position jet pump thru hole in front spar and secure with washer and nut.
D. Connect fuel lines to jet pump.
6. Restore Airplane to Normal
A. Install access panel (Ref 28-11-11, R/I).
B. Remove actuator locks and retract leading edge flaps (Ref 27-81-0, MP).
WARNING: LEADING EDGE FLAPS ARE FAST ACTING AND CAN CAUSE SERIOUS INJURY TO PERSONNEL.
C. Remove electrical power if no longer required (Ref 24-22-0, MP).
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Fuel Scavenge Jet Pump Installation 500
28-15-11 Figure 401 Feb 20/89
Page 402
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