S 284-070

 (11)
 Measure the bonding resistance between these components
 (AMM 20-22-01/601):

 NOTE: The bonding resistance must not be more than 0.010 ohm.
____
 (a)  
The float valve and the tank structure

 (b)  
The bonding jumpers and the tank structure (if the bonding jumpers were loosened).

 F.
Put the Airplane Back To the Usual Condition

 S 214-060
 (1)  Remove all of the unwanted material from the center wing tank (AMM 28-11-00/201).
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A 747-400 MAINTENANCE MANUAL
 (2)  S 414-061Install these spanwise beam access doors (left side of the center wing tank) (AMM 28-11-09/401): (a) 131AZ (b) 131BZ (c) 131CZ (d) 131DZ
 (3)  S 414-062Install these spanwise beam access doors (right side of the center wing tank) (AMM 28-11-09/401): (a) 131AZ (b) 131BZ (c) 132AZ (d) 132BZ
 (4)  S 414-063Install the center wing tank access doors (AMM 28-11-01/401).

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747-400 MAINTENANCE MANUAL
 TASK 28-15-11-404-013
 4.  Float Valve in the No. 2 and 3 Main Tank Removal (Fig. 401)________________________________________________
 A. General
 (1)  
The removal of the float valves in the No. 2 and 3 main tanks is almost the same. Use this procedure to remove the float valves in the No. 2 or 3 main tanks.

 B.
References

 (1)  
AMM 28-11-00/201, Fuel Tanks

 (2)  
AMM 28-11-02/401, Reserve and Main Tank Access Doors

 C.
Access

 (1)  
Location Zones 544 Inbd Main Tank (Part), Mid Spar to Rear Spar, left 644 Inbd Main Tank (Part), Mid Spar to Rear Spar, right

 (2)  
Access Panels
 544AB Main Tank Access Door, Left
 644AB Main Tank Access Door, Right

 D.
Prepare for the removal

 S 654-034
 (1) Defuel the applicable No. 2 or 3 main tank (AMM 28-26-00/201).
 S 864-035
 WARNING:_______OBEY ALL THE FUEL TANK PURGING AND ENTRY PRECAUTIONS. YOU CAN CAUSE AN INJURY TO A PERSON AND CAUSE DAMAGE TO THE AIRPLANE.
 (2)  
Remove all the fuel in the applicable No. 2 or 3 main tank and prepare the main tank for an entry (AMM 28-11-00/201).

 S 014-062

 (3)  
Remove the applicable access door:

 (a)  
Main tank No. 2 access door - 544AB

 (b)  
Main tank No. 3 access door - 644AB

 S 014-073
 WARNING:_______OBEY ALL THE FUEL TANK PURGING AND ENTRY PRECAUTIONS. YOU CAN CAUSE AN INJURY TO A PERSON AND CAUSE DAMAGE TO THE AIRPLANE.
 (4)  Go through the access holes in the ribs to get to the float valve (on the No. 1 rib aft of the mid spar).
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747-400
MAINTENANCE MANUAL

 S 034-063
 (5)  
Disconnect or loosen the bonding jumpers and the tube support brackets if it is necessary.

 S 034-065

 (6)  
Remove the lockwire from the tube coupling nut and the support bracket.

 S 034-064

 (7)  
Disconnect the nut from the float valve.

 S 034-066

 (8)  
Remove the bolt, washer and nut (4 locations) from the float valve.
　
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