Removal of the Buffer Air Tubes [PW11]

TASK 75-26-49-000-801-A
Removal of the Buffer Air Tubes

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

ZONE: 400

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	COVER - PROTECTION
No specific	1	WRENCH - STANDARD

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL, 438AR, 451AL
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR, 461AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-860-833-A	Procedure to Prevent Engine Motoring
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 75-25-49-000-802-A	Removal of the Turbine Cooling Air System
TASK 75-26-01-000-801-A	Removal of the Buffer Air Heat Exchanger
TASK 75-26-03-000-801-A	Removal of the Buffer Air Check Valve
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
Removal of the Buffer Air Tubes - Tube (AD07)
Removal of the Buffer Air Tubes - Tube (AP28)
Removal of the Buffer Air Tubes - Tube (AP24)
Removal of the Buffer Air Tubes - Tube (AP27)
Removal of the Buffer Air Tubes - Tube (AD06)
Removal of the Buffer Air Tubes - Tube (AP29)
Removal of the Buffer Air Tubes - Tubes (AP21) and Duct (AP34)

3. Job Set-up
Subtask 75-26-49-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833)

Subtask 75-26-49-010-050-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 75-26-49-040-050-A ** ON A/C NOT FOR ALL

C. Deactivation of the Thrust Reverser for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-805).

Subtask 75-26-49-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL

4. Procedure

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

Subtask 75-26-49-020-050-D ** ON A/C NOT FOR ALL

CAUTION: USE A SECOND WRENCH TO HOLD THE MATING PARTS WHEN YOU LOOSEN OR TIGHTEN THE TUBE OR HOSE NUTS. IF YOU DO NOT OBEY THIS CAUTION, YOU CAN TWIST OR CAUSE DAMAGE TO THE TUBES OR HOSES.

A. Removal of the Buffer Air Tubes

Removal of the Buffer Air Tubes - Tubes (AP21) and Duct (AP34) ** ON A/C NOT FOR ALL

NOTE: Use a second WRENCH - STANDARD as necessary.

(1) Find the buffer air tubes connected to the Compressor Intermediate Case (CIC) and the buffer air heat exchanger.
(2) Remove the tube (AD07) (3) from the buffer air heat exchanger as follows:
(a) Remove the two bolts (5) and the clamp (4) from the bracket and the tube (AD07) (3).
(b) Remove the coupling (2) and the tube (AD07) (3).
(c) Remove and discard the gasket (1).
(3) Remove the tube (AP43) (Ref. AMM TASK 75-25-49-000-802).
(4) Remove the tube (AP28) (15) from the tubes (AP27) and (AP101) as follows:
(a) Disconnect the two tubes (AP28) (15) B-nuts from the tubes (AP27) and (AP101).
(b) Remove the tube (AP28) (15) from the tubes (AP27) and (AP101).
(5) Remove the tube (AP24) (31) from the buffer air heat exchanger and the duct (AP31) as follows:
(a) Disconnect the wiring harness (WC05) and the Environmental Control System (ECS) harness from the four tubes (AP24) (31) spring clips.
(b) Remove the bolt (5) that attaches the clamp and the manifold (DR121) to the bracket (29).
(c) Remove the three bolts (28) and the bracket (29) from the tube (AP24) (31) and the buffer air heat exchanger.
(d) Remove the bolt (32) and the clamp (27) from the tube (AP24) (31) and the bracket.
(e) Remove the three bolts (33), the three nuts (26), the bracket (34) and the tube (AP24) (31).
(f) Remove and discard the two gaskets (25) and (30).
(6) Remove the tube (AP27) (43) from tube (AP102) and the buffer air heat exchanger as follows:
(a) Disconnect the tube (AP27) (43) B-nut from the tube (AP102).
(b) Remove the three bolts (28) and the tube (AP27) (43).
(c) Remove and discard the gasket (25).
(7) Remove the tube (AD06) (57) from the buffer air heat exchanger and the CIC as follows:
(a) Disconnect the wiring harness (WC11) from the spring clip.
(b) Remove the coupling (55) from the tube (AD06) (57) and the buffer air heat exchanger.
(c) Remove the two bolts (32) and the two clamps (56) from the tube (AD06) (57) and the two brackets.
(d) Remove the four bolts (58), the bracket (59), tube (AD06) (57) and metering plate (53).
(e) Remove and discard the two gaskets (54) and (60).
(8) Remove the buffer air heat exchanger (Ref. AMM TASK 75-26-01-000-801).
(9) Remove the tube (AP29) (71) from the manifold (AP26) and the manifold (AP30) as follows:
(a) Remove the two bolts (5) and the two clamps (70) from the tube (AP29) (71) and the two brackets.
(b) Disconnect the tube (AP29) (71) B-nut from the manifold (AP30).
(c) Remove the three bolts (72), the tube (AP29) (71) and the metering seal (74).
(d) Remove and discard the gasket (73).
(10) Remove the manifold (AP26) (85) from the manifold (AP21) and the duct (AP34) as follows:
(a) Remove the three bolts (28), the three bolts (72) and the manifold (AP26) (85).
(b) Remove and discard the gaskets (84) and (86).

POST SB C-75-00-0007A

(11) Remove the tube (AP22) (99) from the Low Pressure Compressor (LPC) buffer air valve and the duct (AP34) as follows:
(a) Remove the three bolts (72) and the bracket (103) from the tube (AP22) (99) and the duct (AP34).
(b) Remove the two bolts (5) and the clamp (98) from the tube (AP22) (99) and the bracket.
(c) Remove the three bolts (97), the bracket (96), the three nuts (102), and the tube (AP22) (99).
(d) Remove and discard the gaskets (86) and (104).
(e) Disconnect the tube (AS41) (101) B-nut from the air pressure sensor.
(f) Remove the two bolts (72) and the tube (AS41) (101).
(g) Remove and discard the gasket (100).

END OF POST SB C-75-00-0007A

(12) Remove the tube (AP23) (116) from the duct (AP34) and the CIC as follows:
(a) Remove the three bolts (72) from the tube (AP23) (116) and the duct (AP34).
(b) Remove the bolt (118) and the clamp (117) from the bracket (119).
(c) Remove the three bolts (72), the bracket (119), tube (AP23) (116) and metering seal (114).
(d) Remove and discard the gaskets (73) and (115).
(13) Remove the buffer air check valve (Ref. AMM TASK 75-26-03-000-801).

POST SB C-72-00-0058A

(14) Remove the manifold (AP21) (131) and the duct (AP34) (132) from the CIC as follows:
(a) Remove the three bolts (28) and the duct (AP34) (132).
(b) Remove the bolt (5) from the clamp (130) and the bracket (129).
(c) Remove the three bolts (72) and the bracket (129) from the manifold (AP21) (131) and the CIC.
(d) Remove the two bolts (28), the three bolts (133) and the manifold (AP21) (131).
(e) Remove the metering seals (114) and (134).
(f) Remove and discard the two gaskets (115).

END OF POST SB C-72-00-0058A

CAUTION: INSTALL PROTECTION COVERS ON ALL THE OPENINGS IMMEDIATELY TO PREVENT DAMAGE TO THE ENGINE.

(15) Make sure that you install the COVER - PROTECTION as necessary to prevent damage to the engine.

[Rev.10 from 2021] 2026.04.01 03:13:23 UTC