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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 034-157
 (5)  Loosen the drain plug (13), 1/4 turn, before you remove the fasteners from the motor/impeller unit (4).
 NOTE: Do not remove the drain plug or fuel leakage can occur.
____
 S 034-183
 (6)  
Do these steps to remove the bonding jumpers:

 (a)  
PUMPS WITH A BRACKET MOUNTED ELECTRICAL CONNECTOR; Remove the bolt (21), washers (19) (two locations), and nut (20) that attach the bonding jumper (16) to the electrical connector bracket (View E).

 CAUTION:_______REMOVE ONLY THE SOCKET HEAD SCREWS (17). DO NOT REMOVE THE HOUSING MOUNTING BOLTS. IF YOU REMOVE THE HOUSING MOUNTING BOLTS, FUEL LEAKAGE FROM THE TANK CAN OCCUR.
 CAUTION: DO NOT PULL THE MOTOR/IMPELLER UNIT AWAY FROM THE REAR
_______ SPAR UNTIL YOU INSTALL THE RETENTION SCREWS. THE RETENTION SCREWS WILL HELP YOU TO QUICKLY INSTALL THE MOTOR/IMPELLER UNIT AGAIN IF THERE IS A FUEL LEAK.
 (b)  Remove the socket head screws (17) and washers (18) (five locations) that hold the motor/impeller unit (4) to the pump housing (View B-B).
 NOTE: Do not pull the motor/impeller unit away from the rear
____ spar until you install the retention screws.
 (c)  Remove the bonding clip(s).
 NOTE: Do not disassemble the bonding jumpers from the
____ bonding clip(s) or the housing mounting bolt(s) on the rear spar.
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 654-158
 (7)  
Do these steps to drain the fuel from the motor/impeller unit (4).

 (a)  
Install the MS35275-250 retention screws at the 2 o'clock and 6 o'clock positions (View B-B).

 (b)  
Put an applicable container below the motor/impeller unit (4).

 (c)  
Pull the handle on the motor/impeller unit (4) until the motor/impeller unit (4) is against the retention screws.

 WARNING:_______MAKE SURE THE FLOW OF FUEL STOPS. IF THERE IS A CONTINUOUS FLOW OF FUEL, THE INLET CHECK VALVE IS NOT CLOSED. INSTALL THE MOTOR/IMPELLER UNIT AGAIN AND DEFUEL THE TANK BEFORE THE MOTOR/IMPELLER UNIT IS REMOVED. FUEL FLOW FROM THE INLET CHECK VALVE CAN CAUSE A DANGEROUS CONDITION FOR EQUIPMENT AND PERSONS.

 (d)  
Remove the drain plug (13) and let the motor/impeller unit (4) drain into a container.

 (e)  
Discard the packing (14).

 (f)  
After the motor/impeller unit (4) drains, remove the retention screws from the motor/impeller unit (4).

 S 024-159
 (8)
Do these steps to remove the motor/impeller unit (4) (View A):

 (a)  
Pull the motor/impeller unit (4) straight back from the housing.

 (b)  
Remove the coupling (9) from the top of the motor/impeller unit

 (4)
 and keep it for the installation. 1) Discard the packing (10) (two locations).

 (c)  
Discard the packing (6, 7 and 8) from the motor/impeller unit (4).

 (d)  
Remove the pressure switch (3) from the motor/impeller unit (4) and keep it for the installation. 1) Discard the packing (1).

 S 214-017
 (9)  Do a visual check of the inside of the housing to make sure it is not damaged.
 TASK 28-31-01-404-018
 3.  Fuel Override/Jettison Pump Motor/Impeller Unit Installation (Fig. 401)____________________________________________________________
 A. Reference
 (1)  AIPC 28-31-01 Fig. 2
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