S 016-023-N00

 (2)  
Open the fan cowl panels (AMM 71-11-04/201).
 S 016-024-N00

 (3)  
Open the core cowl panels (AMM 71-11-06/201).

 S 016-025-N00 WARNING: OBEY THE INSTRUCTIONS IN AMM 78-31-00/201 TO OPEN THE THRUST
_______ REVERSERS. IF YOU DO NOT OBEY THE INSTRUCTIONS, INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR.
 (4)  Open the thrust reversers (AMM 78-31-00/201).
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 75-33-00
 ALL  ú ú N01 Page 609 ú Jun 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
E. Do the Inspection of the Position Indicators (Fig. 601)
 S 216-026-N00
 (1)  Examine the position of the position indicator pins in the control valves.
 NOTE: Position indicators pins are in the TCA (Turbine Cooling
____ Air) valves. The valves are found at the 9:30 and 3 o'clock positions on the HPC case.
 NOTE: Position indicators pins are in the TRC (Thermatic Rotor
____ Control) valves. The valves are found at the 9:30 and 3:30 o'clock positions on the HPC case.
 (a)  If the position indicator pins are not fully extended, replace the defective control valve as it is necessary (AMM 75-33-01/401).
 NOTE:____TCA System: If the position indicator pin is not in the up position, the valve is stuck in the closed position. The valve must be replaced in ten (10) days or less.
 NOTE:____TRC System: If the position indicator pin is not in the up position, the valve is stuck in the closed position. The valve must be replaced in 500 hours or less.
 F. Put the Airplane Back to Its Usual Condition
 S 416-027-N00
 WARNING: OBEY THE INSTRUCTIONS IN AMM 78-31-00/201 TO CLOSE THE THRUST
_______ REVERSERS. IF YOU DO NOT OBEY THE INSTRUCTIONS, INJURIES TO PERSONS AND DAMAGE TO EQUIPMENT CAN OCCUR.
 (1)  
Close the thrust reversers (AMM 78-31-00/201).

 S 416-028-N00

 (2)  
Close the core cowl panels (AMM 71-11-06/201).

 (3)  
Close the fan cowl panels (AMM 71-11-04/201).

 S 446-030-N00

 (4)  
Do the activation procedure for the thrust reversers
 (AMM 78-31-00/201).

 S 416-029-N00
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
HPC SECONDARY FLOW CONTROL VALVE - REMOVAL/INSTALLATION
_______________________________________________________
 1.  General
_______
 A.  This procedure is for engines without the Phase 3 changes. Phase 3
 engines do not have these valves.

 B.  This procedure gives the instructions for the removal and installation of the left and right control valves for the High Pressure Compressor (HPC) secondary flow. The control valves for the HPC secondary flow will be referred to as the control valves for this procedure. The differences between the removal and installation of the left and right control valves are given in the procedure.
 C.  The control valves are installed on the HPC forward case at the 3:30 and
 9:30
 o'clock positions.

 D.  
You can get access to the control valves through the applicable thrust
 reverser half.

 TASK 75-33-01-004-001-N00
 2.  Remove the HPC Secondary Flow Control Valve (Fig. 401)
___________________________________________
 A.  References
 (1)  
AMM 36-11-01/401, Pneumatic Manifold

 (2)  
AMM 71-11-04/201, Fan Cowl Panels

 (3)  
AMM 71-11-06/201, Core Cowl Panels

 (4)  
AMM 78-31-00/201, Thrust Reverser System

 (5)  
IPC 75-20-01 Fig. 1

 (6)  
IPC 75-33-01 Fig. 1

 B.  
Access