S 014-007-N00
 (7)  
For the lower center aft and aft cooling air tubes, remove the aft oil vent tube for the No. 3 bearing with the steps that follow (views A and E):

 (a)  
Disconnect the tube nut for the oil vent tube from the internal tube for the turbine exhaust case.

 (b)  
Disconnect the tube nut at the tube connection to the rear of the flange M.

 (c)  
Remove the bolt and nut which attach the tube clamp for the oil vent tube and the adjacent tube clamp to the flange P bracket.

 (d)  
Remove the bolt and nut which attach the tube clamp for the oil vent tube to the adjacent tube to the rear of the flange P.

 (e)  
Remove the bolt and nut which attach the tube clamp for the oil vent tube to the flange P bracket.

 (f)  
Remove the bolt and nut which attach the tube clamp for the oil vent tube and the adjacent tube clamp to the bracket on the flange N.

 (g)  
Remove the bolt and nut which attach the tube clamp for the oil vent tube to the adjacent tube clamp between the flange N and flange P.

 (h)  
Remove the oil vent tube.

 (i)  
Install the protection caps to the openings from the oil vent tube.

 S 014-009-N00
 (8)  
For the lower cooling air tubes (but not the aft cooling air tube), remove the No. 3 TVC air duct (AMM 75-24-02/401).

 S 014-010-N00

 (9)  
For the lower cooling air tubes (but not the aft cooling air tube), remove the deoiler outlet tube from the engine.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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S 014-011-N00
 (10) For the lower forward and center forward cooling air tubes, remove the forward oil vent tube for the No. 3 bearing with the steps that follow (views E and I):
 (a)  
If it is not done, disconnect the tube nut at the tube connection to the rear of the flange M.

 (b)  
Disconnect the tube nut from the adapter on the diffuser case.

 (c)  
Remove the bolt and nut which attach the tube clamp for the oil vent tube to the adjacent tube clamp on the diffuser case.

 (d)  
Remove the oil vent tube.

 (e)  
Install the protection caps to the openings from the oil vent tube.

 S 014-013-N00
 (11) For the lower aft cooling air tube, remove the aft EEC PT4.95 pressure tube with the steps that follow (views A and E):
 (a)  
Disconnect the tube nut for the EEC PT4.95 pressure tube from the tube adapter on the exhaust case.

 (b)  
Disconnect the tube nut from the tube adapter to the rear of the flange N.

 (c)  
Remove the EEC PT4.95 pressure tube from the engine.

 (d)  
Install the protection caps on the openings of the EEC PT 4.95 pressure tube.

 S 014-015-N00
 (12) For the lower cooling air tubes (but not the aft cooling air tube), remove the EEC PT4.95 pressure tube between the diffuser and HPT cases with the steps that follow (views A and I):
 (a)  
Disconnect the tube nut from the tube adapter to the rear of the flange N, if it is not done.

 (b)  
Disconnect the tube nut from the tube adapter at the diffuser case.

 (c)  
If it is not done, remove the bolt and nut which attach the tube clamp for the EEC PT4.95 pressure tube to the adjacent tube clamp.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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 ALL  ú ú N01 Page 415 ú Oct 10/97
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
(d)  
Remove the bolt and nut which attach the tube clamp for the EEC PT4.95 pressure tube to the bracket at two locations.

 (e)  
Install protection caps on the openings of the EEC PT4.95 pressure tube.

 S 014-109-N00
 (13)
 For the lower center cooling air tubes, remove the bolt, washers, and nut which attach the electrical wire clamp for the start valve to the flange M bracket at two locations (view E).
　
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