S 014-019-N00

 (14)
 For the lower forward cooling air tube, disconnect the left accessory cooling tube with the steps that follow (view E and N):

 (a)  
Disconnect the forward tube nut at the aft face of the intermediate case at the 6 o'clock position.

 (b)  
Remove the bolt, washer, and nut which attach the tube clamp to the heat shield at the 6 o'clock position.

 (c)  
Remove the bolt, nut, and washers which attach the tube clamp to the flange M bracket at approximately the 6 o'clock position.

 (d)  
Remove the bolt, washers, nut, and clamp which attach the cooling air tube to the flange M bracket at approximately the 7 o'clock position.

 (e)  
Remove the bolt, washers, and nut which attach the tube clamp to the adjacent tube and wire bundle clamps at two locations on the diffuser case.

 (f)  
Remove the bolt, washers, and nut which attach the tube clamp to the wire bundle clamp on the diffuser case.

 (g)  
Remove the bolts and washers which attach the tube clamps to the brackets on the main gearbox.

 (h)  
Remove the bolt, washer, and nut which attach the tube clamp to the adjacent tube clamp on the forward HPC case.

 (i)  
Install the protection caps to the tube adapter and tube nut.

 S 014-112-N00
 (15)
 For the lower aft cooling air tube, disconnect the support tube for the support tube with the steps that follow (views B, G, and H):

 (a)  
Remove the bolt and nut which attach the tube clamp for the support tube to the bracket on the flange N bracket approximately at the 4 o'clock position.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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(b)  
Remove the bolt and nut which attach the tube clamp for the support tube to the bracket on the aft flange of the No. 2 TVC air duct.

 (c)  
Remove the bolt and nut which attach the tube clamp for the support tube to the bracket on the bridge bracket for the LPT tube at the 5:30 o'clock position.

 (d)  
Remove the bolt and nut which attach the support tube and wire harness clamps to the flange P bracket at the 5:30 o'clock position.

 S 014-026-N00
 (16) For the lower forward cooling air tube, remove the support bracket for the heat shield and flange M bracket at approximately the 6:30 o'clock position with the steps that follow (view M):
 (a)  
Remove the bolts, washers, and nuts which attach the support bracket for the heat shield to the heat shield and flange M bracket.

 (b)  
Remove the support bracket.

 (c)  
Remove the bolts, washers, and nuts which attach the support bracket for the heat shield of the start valve to the flange M bracket. 1) Remove the support bracket with the heat shield.

 (d)  
Remove the bolts and nuts which attach the bracket to the flange M.

 (e)  
Remove the flange M bracket.

 S 014-028-N00
 (17) For the lower forward cooling air tube, remove the heat shield at approximately the 4:30 o'clock position on the diffuser case with the steps that follow (view F):
 (a)  
Remove the bolts which attach the heat shield to the flange M bracket.

 (b)  
Remove the nuts and washers which attach the two heat shields together.

 (c)  
Remove the bolts and screw which attach the triangular bracket to the heat shield.

 (d)  
To remove the heat shield from the engine, move the heat shield in the up and out direction.

 S 014-114-N00
 (18) For the lower aft cooling air tube, remove the bolts and nuts which attach the bracket to the flange N at the 8 o'clock position (view E).
 (a)  Remove the cooling air tube.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 75-24-07
 ALL  ú ú N01 Page 417 ú Oct 10/97
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
　
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