(a)
Tighten the screw to 15-20 pound-inches (1.7-2.3 N.m).

 F.
Put the Airplane Back to Its Usual Condition

 S 412-028
 WARNING: OBEY THE INSTRUCTIONS IN THE PROCEDURE TO CLOSE THE THRUST
_______ REVERSERS. IF YOU DO NOT OBEY THE INSTRUCTIONS WHEN YOU CLOSE THE THRUST REVERSERS, INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR.
 (1)  Close the right thrust reverser (Ref 78-31-00/201).
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A 747-400 MAINTENANCE MANUAL
 (2)  S 412-029Close the right core cowl panel (Ref 71-11-06/201).
 (3)  S 412-030Close the right Fan cowl panel (Ref 71-11-04/201).
 (4)  S 442-031Do the activation procedure for the thrust reverser (Ref 78-31-00/201).

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A
747-400 MAINTENANCE MANUAL
 FAN AIR MODULATING VALVE - REMOVAL/INSTALLATION
_______________________________________________
 1.  General_______
 A. This procedure contains the following removal and installation tasks.
 (1)  
Removal of the Fan Air Modulating Valve.

 (2)  
Installation of the Fan Air Modulating Valve.

 (3)  
Removal of the Fan Air Modulating Valve Air Filter.

 (4)  
Installation of the Fan Air Modulating Valve Air Filter.

 B.  
The fan air modulating valve is installed on the right side of the precooler. It is necessary to open the right half of the thrust reverser to get access to the fan air modulating valve.

 TASK 36-12-04-004-027
 2.  Remove the Fan Air Modulating Valve (Fig. 401)___________________________________
 A.  References
 (1)  
AMM 71-11-04/201, Fan Cowl Panels

 (2)  
AMM 71-11-06/201, Core Cowl Panels

 (3)  
AMM 78-31-00/201, Thrust Reverser System

 B.  
Access

 (1)  
Location Zone 412 Engine 1 - High Pressure Compressor Case 12:00 422 Engine 2 - High Pressure Compressor Case 12:00 432 Engine 3 - High Pressure Compressor Case 12:00 442 Engine 4 - High Pressure Compressor Case 12:00

 (2)  
Access Panel
 416 Right Thrust Reverser Half - Engine 1
 426 Right Thrust Reverser Half - Engine 2
 436 Right Thrust Reverser Half - Engine 3
 446 Right Thrust Reverser Half - Engine 4

 C.  
Prepare to Remove the Fan Air Modulating Valve

 S 044-002
 WARNING: DO THE DEACTIVATION PROCEDURE FOR THE THRUST REVERSER TO
_______ PREVENT THE OPERATION OF THE THRUST REVERSER. ACCIDENTAL OPERATION OF THE THRUST REVERSER CAN CAUSE INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT.
 (1)  Do the deactivation procedure for the thrust reverser for ground maintenance (AMM 78-31-00/201).
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A

747-400 MAINTENANCE MANUAL
SEE A
PRECOOLER (REF) 
1. FAN AIR 
MODULATING 
VALVE 
2. COUPLING 
SEE  B 

FAN AIR TEMPERATURE SENSOR COOLING AIR PORT
3. ELBOW
4. JAM NUT A 5. O-RING
Fan Air Modulating Valve Installation
Figure 401 (Sheet 1)

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