(2)  
IPC 21-62-56 Fig. 1 and 2

 B.  Access
 (1)  Location Zone
 133 Air Conditioning Equipment Bay, LH
 134 Air Conditioning Equipment Bay, RH

 C.  Prepare for the Removal
 S 014-002
 (1) Do the Fan Diffuser And Inlet Housing Removal (Ref 21-51-07/401).
 D.  Remove the Screen
 S 214-003
 (1)  
If a part of the screen is not there or is damaged, make sure the fan is not damaged.

 S 034-004

 (2)  
Use a knife to break the adhesive between the screen and the fan housing.

 NOTE: Access to the adhesive is through the fan housing.
____
 S 024-019
 (3)  Remove the screen from the fan housing.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 21-51-15
 ALL  ú ú 01 Page 401 ú Feb 10/93
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

PACK 2 RAM AIR DUCT
FWD
PACK 1 RAM
AIR DUCT PACK 3 SCREEN SEE A
RAM AIR DUCT SEE B
AIR CONDITIONING
EQUIPMENT BAY

RAM AIR DUCT
FWD
AIR CYCLE MACHINE (REF)
PACK 1 (TYPICAL)
A
ADHESIVE
SCREEN
FAN INLET
FLOW  B
Ram Air System Screen Installation Figure 401
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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 ALL  ú ú 01 Page 402 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 034-020
 (4)  Use the knife to remove the adhesive.
 TASK 21-51-15-404-006
 3.  Ram-Air Screen Installation (Fig. 401)___________________________
 A. Standard Tools and Equipment
 (1)  Lint-free wiping material (cloth or paper)
 B. Consumable Materials
 (1)  
A00138 Sealant - BMS 5-19, Class B 1/2

 (2)  
B01011 Solvent - Final Cleaning of Composites Prior to Non-structural bonding (Series 91) (AMM 20-30-91)

 C. References
 (1)  
21-51-07/401, Fan Diffuser and Inlet Housing

 (2)  
IPC 21-62-56 Fig. 1 and 2

 D. Access
 (1)  Location Zone
 133 Air Conditioning Equipment Bay, LH
 134 Air Conditioning Equipment Bay, RH

 E. Prepare for the Installation
 S 114-014
 WARNING: DO NOT GET SOLVENTS IN YOUR MOUTH, OR YOUR EYES, OR ON YOUR
_______ SKIN. DO NOT BREATHE THE FUMES FROM SOLVENTS. SOLVENTS ARE HAZARDOUS MATERIALS. SOLVENTS MAY BE FLAMMABLE OR HARMFUL TO THE ENVIRONMENT. REFER TO PRODUCT MATERIAL SAFETY DATA SHEETS (MSDS) AND LOCAL REQUIREMENTS FOR PROPER HANDLING PROCEDURES.
 (1)  
Use a solvent, Series 91 (AMM 20-30-91) to remove all of the adhesive from the fan housing.

 S 164-015

 (2)  
Use the lintfree cloth to dry the fan housing.

 F. Install the Screen
 S 324-016
 (1)  Mix the sealant with its activator as specified in the manufacturer's instructions.
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 394-010
 (2)  
Apply a thin layer of the sealant to the mating surfaces of the fan housing and the screen.

 S 424-017

 (3)  
Immediately put the screen in its position against the fan housing.

 S 424-018

 (4)  
Push the screen against the fan housing until the sealant comes out all around the screen.

 S 864-011

 (5)  
Let the sealant cure at the room temperature (below 100°F (37.8°C)) for the time that is shown on the sealant container.
　
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