(a)  
Install the G28019-18 pressure test door, into an access door opening for the fuel tank that will be pressurized (View B).

 (b)  
Install all other access doors for the fuel tank that is to be pressurized.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-00
 ALL  ú ú 07 Page 654 ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

 WARNING: BLOW INTO THE MANOMETER HOSE AND MAKE SURE THE WATER LEVEL
_______ CHANGES TO MAKE SURE THE WATER MANOMETER ASSEMBLY OPERATES SAFELY. MAKE SURE THE OPEN END OF THE MANOMETER IS FULLY FREE OF ALL BLOCKAGE. IF THE MANOMETER IS NOT CLEAR, INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR.
 (c)  
Connect the water manometer, F72951-1, air supply hose, pressure gage and shutoff valve to the pressure test door.

 WARNING:_______DO NOT GO INTO A FUEL TANK THAT IS PRESSURIZED. DO NOT USE MORE THAN THE MAXIMUM SAFE PRESSURE OF 5.20 PSIG. IF YOU GO INTO A PRESSURIZED FUEL TANK OR USE MORE THAN THE MAXIMUM SAFE PRESSURE, YOU COULD CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.

 (d)  
Supply 4.0 psig air pressure to the fuel tank.

 (e)  
Supply 20-25 psig to the fuel-feed and refuel/jettison manifold (AMM 28-22-07/601).

 L.
Find the Leak(s) in the Fuel Tank

 S 286-384
 (1)  
Do these steps to find the tank end leak(s):

 (a)  
Go into the adjacent fuel tank (AMM/28-11-00/201).

 (b)  
Go to the tank end structure next to the pressurized fuel tank.

 (c)  
Apply the bubble solution to the tank end structure.

 (d)  
Watch the area that you think contains the leak for bubbles.

 NOTE: The size of the leak can cause the bubbles to show very
____ slowly. It can be necessary to constantly watch the area to find the leak.
 (e)  
Make a mark at the locations where you see bubbles.

 (f)  
Use a moist cloth to remove the bubble solution from the fuel tank.

 (g)  
Remove pressure from the fuel tank.

 (h)  
Remove the pressure from the fuel system manifolds (AMM 28-22-00/601).

 S 366-385
 (2)
Repair or replace the sealant as necessary (AMM 28-11-00/801).

 M.
Return the Airplane to the Usual Condition

 S 046-386
 (1)  
Disconnect the water manometer, air supply hose and shutoff valve from the pressure test door.

 (2)  
Remove the pressure test door, B28019-18.

 S 086-302
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-00
 ALL  ú ú 08 Page 655 ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 
747-400 
MAINTENANCE MANUAL
 S 046-387
 (3)  Remove the fuel system manifold pressure test equipment
 (AMM 28-22-07/401).
 S 866-397
 (4)  Put the engine area back to the usual condition (AMM 28-22-07/601).
 S 866-388
 (5)  Go to the left and right pressure refuel stations and do these
 steps:
 (a) Use the manual handles to close these valves:
 1) Left and right fuel shutoff valve
 2) Left and right defuel valve
 a) Put lockwire on the defuel valve handles.
 (b) Use the manual handles to put these valves in the CLOSED
 position:
 1) Engine No. 1 Spar Valve (AMM 28-22-01/401)
 2) Engine No. 1, 2, 3, and 4 crossfeed valves
 (AMM 28-22-02/401).
 (c) AIRPLANES WITH A HYDROMECHANICAL FUEL SCAVENGE SYSTEM;
 Install the fuel scavenge system fuel strainers.
 S 086-303
 (6)  Go into the reserve tank and do these steps:
 (a) Remove the tools installed for the pressure check (Table 602).
 (b) Install the coupling in the vent line at WS 1392
　
中國航空網 m.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 燃油 FUEL 1(77)