75-24-09
 ALL  ú ú N02 Page 423 ú Jun 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
(f)  
Disconnect the middle tube nut of the pressure tube for the No. 4 bearing (View AK).

 (g)  
Remove the three bolts and nuts that attach the clamps for the pressure tubes for the No. 4 bearing (Views AB, AG and AH).

 (h)  
Remove the six bolts that attach the clamps for the pressure tubes for the No. 4 bearing (Views AC, AD, AF, AJ and AI).

 (i)  
Remove the two pressure tubes for the No. 4 bearing from the engine.

 (j)  
Install protection caps to the open ends of the pressure tubes for the No. 4 bearing.

 S 014-009-N00
 (9)  
ENGINES PRE-PW-SB 79-76; For the lower cooling air tubes, remove the oil vent tube for the No. 3 bearing with the steps that follow:

 (a)  
Disconnect the tube nut for the oil vent tube from the internal tube of 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 Flange P bracket.

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

 (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 from the engine.

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

 S 014-010-N00
 (10)
 ENGINES PRE-PW-SB 79-76; For the lower cooling air tubes, remove the PT4.95 pressure tube for the EEC with the steps that follow:

 (a)  
Disconnect the tube nut from the tube coupling at the approximately 7 o'clock position on the turbine exhaust case.

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 75-24-09
 ALL  ú ú N02 Page 424 ú Jun 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
(b)  
Remove the bolt and nut that attaches the tube clamp to the Flange P bracket at the 7 o'clock position.

 (c)  
Disconnect the tube nut from the tube adapter to the rear of the Flange N.

 (d)  
Remove the PT4.95 pressure tube from the engine.

 (e)  
Install protection caps to the openings in the PT4.95 pressure tube.

 S 014-076-N00
 (11) ENGINES POST-PW-SB 79-76; For the lower cooling air tubes, remove the oil vent tube for the No. 3 bearing and the PT4.95 pressure tube with the steps that follow:
 (a)  
Disconnect the tube nut of the vent tube for the No.3 bearing from the internal tube on the turbine exhaust case.

 (b)  
Disconnect the tube nut of the vent tube for the No.3 bearing from the tube adapter to the rear of the Flange N.

 (c)  
Disconnect the PT4.95 pressure tube from the tube nut at the turbine exhaust case.

 (d)  
Disconnect the tube nut at the PT4.95 pressure tube connection to the rear of the Flange N.

 (e)  
Remove the three bolts and nuts that attach the clamps for the oil vent tube for the No. 3 bearing and the PT4.95 pressure tube (Views AW, AX, AY).

 (f)  
Remove the two bolts that attach the clamps for the oil vent tube for the No. 3 bearing and the PT4.95 pressure tube (View AV).

 (g)  
Remove the oil vent tube for the No. 3 bearing and the PT4.95 pressure tube from the engine.

 (h)  
Install protection caps to the open ends of the tubes.

 S 014-011-N00
 (12) For the two lower aft cooling air tubes, remove the lower support bracket on the Flange P with the steps that follow:
 (a)  
Remove the bolts and nuts which attach the support bracket to the Flange P.
　
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