(a)  
Do a visual check to make sure the access door installation is fluid tight.

 (b)  
Do a fuel leak check for the surge tank access doors.

 1)  Do this task: Wing Surge Tank Float Switch Operational Test (AMM 28-21-12/501).
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-03
 ALL  ú ú 01 Page 406 ú Oct 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 FUEL SUMP DRAIN VALVE PRIMARY POPPET - REMOVAL/INSTALLATION
___________________________________________________________
 1.  General_______
 A.  This procedure contains instructions to remove and install the primary poppet of a mechanically-actuated fuel sump drain valve.
 B.  A primary poppet is installed in each fuel sump drain valve. The fuel sump drain valves are found below the wing. The fuel sump drain valve for the outboard main tank is found below the inboard main tank. The fuel sump drain valve for the reserve tank is found below the outboard main tank.
 C.  Replace the primary poppet with the fuel in the tank so you can do a test of the fuel sump drain valve operation.
 TASK 28-11-04-004-001
 2.  Fuel Sump Drain Valve Primary Poppet Removal (Fig. 401)____________________________________________
 A.  Standard Tools and Equipment
 (1)  
Standard 1 1/16 inch socket

 (2)  
1 1/16 inch thin wall socket

 B.  
References

 (1)  
AIPC 28-11-04, Fig. 1

 (2)  
AIPC 28-11-07, Fig. 1

 C.  
Access

 (1)  
Location Zones 131 Center Section Wing Box, Left 132 Center Section Wing Box, Right 541 Inbd Main Tank (Part), Front Spar to Mid Spar, Left 545 Inbd Main Tank (Part), Mid Spar to Rear Spar, Left 552 Outbd Main Tank (Part), Mid Spar to Rear Spar, Left 555 Surge Tank, Front Spar to Rear Spar, Left 641 Inbd Main Tank (Part), Front Spar to Mid Spar, Right 645 Inbd Main Tank (Part), Mid Spar to Rear Spar, Right 652 Outbd Main Tank (Part), Mid Spar to Rear Spar, Right 655 Surge Tank, Front Spar to Rear Spar, Right

 (2)  
Access Panels
 191GL Fuel Drain and Dripstick Access Door
 192GR Fuel Drain and Dripstick Access Door

 D.  
Procedure

 S 014-002
 (1)  To remove the primary poppet for the fuel sump drain valve in the center wing tank, open the access door, 191G or 192G, below the center wing section.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-04
 ALL  ú ú 04 Page 401 ú Oct 10/93
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 034-003
 (2)  
For all the fuel sump drain valve locations except the No. 2 or No. 3 main tank, turn the poppet seat (4) in the counterclockwise direction with a standard 1 1/16 inch socket wrench to loosen it.

 S 034-019

 (3)  
For the fuel sump drain valves on the No. 2 or No. 3 main tank, turn the poppet (4) in the counterclockwise direction with a 1 1/16 inch thin wall socket wrench to loosen it.

 S 024-004

 (4)  
Remove the poppet seat (4) with the primary poppet (3).

 NOTE: Some leakage can occur when you remove the poppet seat (4).
____ But, the secondary poppet engages before the primary poppet seat (4) completely disengages and the leakage must stop.
 S 034-014
 (5)  Discard the packings (1) and (2).
 TASK 28-11-04-404-005
 3. Fuel Sump Drain Valve Primary Poppet Installation (Fig. 401)
_________________________________________________
 A. Standard Tools and Equipment
 (1)  
Standard 1 1/16 inch socket

 (2)  
1 1/16 inch thin wall socket

 B.
Consumable Materials

 (1)  
B00148 Solvent - Methyl Ethyl Ketone (MEK), TT-M-261

 (2)  
D00010 Compound - Anti-seize, MIL-A-907

 C.
Parts