S 144-008

 (10)
 Use the knife to remove the seal from the surface of the airplane skin.

 S 034-009

 (11)
 Put a cover on the duct opening.

 TASK 21-58-12-404-010
 3. Ground Exhaust Valve Installation (Fig. 401)
_________________________________
 A. Parts ~.............................................................................. | MM | | IPC | ................. ............................ | FIG | ITEM | NOMENCLATURE | SUBJECT | FIG | ITEM | ................................................................................
 |  401 |  1  | Screw  |  21-58-12 | 01  |  15  |
 |  |  2  | Washer  |  |  |  20  |
 |  |  3  | Nut  |  |  |  25  |
 |  |  5  | Coupling  |  |  |  50  |
 |  |  6  | Bolt  |  |  |  30  |
 |  |  7  | Bolt  |  |  |  35  |
 |  |  8  | Gasket  |  |  |  45  |
 |  |  9  | Valve  |  |  |  55  |

 2.......….......…...................................…...........….....…........1
 B. References
 (1)
24-22-00/201, Manual Control

 (2)
51-31-01/201, Seals and Sealing

 (3)
WDM 21-58-16

 (4)
SSM 21-58-06

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 ALL  ú ú 01 Page 404 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

 C. Equipment
 (1) Sandpaper, 400 to 600 grit aluminum Oxide - Commercially available
 D. Consumable Materials
 (1)  
B00148 solvent, Methyl Ethyl Ketone (MEK)

 (2)  
A00247 - Sealant, BMS 5-95 Class B-2

 E. Access
 (1)  Location Zone
 122 Forward Cargo Compartment Forward Half, RH

 F. Install the Valve
 S 434-011
 (1)  Remove the cover from the duct opening.
 (a)  Make sure there is no unwanted material in the duct.
 S 434-012
 (2) Install a new gasket (8) in its position on the airplane skin.
 (a)  Make sure you align the hole for the manual drive collar.
 S 424-013
 (3)  
Put the valve (9) in its position.

 S 434-025

 (4)
Install the bolts (6 and 7) from the outer side of the airplane.

 (a)  Make sure the short bolt (6) is in the correct location.
 S 434-014
 (5)
Install the coupling (5) that holds the valve (9) to the duct (4).

 S 394-015

 (6)  
Use the sealant to apply an aerodynamic smoother seal between the valve and the airplane skin (Ref 51-31-01/201).

 S 114-067

 (7)  
Clean the bond surfaces of the ground strap on the valve assembly as follows:

 (a)  
Use 400 to 600 grit aluminum oxide sandpaper to prepare the bond surfaces of the ground strap so that all surface finishes are removed and bright metallic bond surfaces are visable. 1) Remove the minimum amount of material necessary to get a

 bright metallic surface.

 (b)  
Remove metal particles, dirt and any other contaminants from the bond surfaces as follows: 1) Pour clean, uncontaminated B00148 solvent, Methyl Ethyl

 Ketone (MEK), ASTM D740, onto clean BMS15-5, Class A
 absorbent wipers.
 2) Wipe the surface with the solvent soaked wiper.
 3) Immediately wipe surfaces dry with clean dry wipers until
 all solvent is removed from the surfaces.
 (c)  Repeat the above three steps until the wiper shows no visible contamination or discoloration.
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