Removal of the LPC Buffer Air Valve [PW11]

TASK 75-26-02-000-801-A
Removal of the LPC Buffer Air Valve

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
FIN: 4101JM ** ON A/C NOT FOR ALL

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

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, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-860-832-A	Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
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
LPC Buffer Air Valve
LPC Buffer Air Valve

3. Job Set-up
Subtask 75-26-02-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832)

Subtask 75-26-02-010-050-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 75-26-02-040-050-A ** ON A/C NOT FOR ALL

C. Deactivation of the Thrust Reverser System for Ground 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 ground maintenance (Ref. AMM TASK 78-30-00-040-805).

Subtask 75-26-02-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the right thrust reverser cowl-door (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
462AR

4. Procedure

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

Subtask 75-26-02-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the Low Pressure Compressor (LPC) Buffer Air Valve
(1) Removal of the protection covers:

CAUTION: REMOVE THE PROTECTION COVERS FROM THE OPENINGS AS NECESSARY TO PREVENT ENGINE DAMAGE.

(a) Make sure that you remove all the necessary COVER - PROTECTION to prevent damage to the engine.
(2) Find the LPC buffer air valve (1) on the LPC approximately at the 2 o'clock position.

PRE SB C-75-00-0022A (Initial Design Configuration)

(3) Remove the LPC buffer air valve (1) from the tube (AP22), duct (AP32) and tube (AA25) as follows:

LPC Buffer Air Valve ** 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) Disconnect the tube (AA25) from the LPC buffer air valve (1).
(b) Remove the three nuts (16) and the three bolts (11).
(c) Remove the coupling (14) from the duct (AP32) and the LPC buffer air valve (1).
(d) Loosen the two bolts (12) and the clamp that attach the tube (AP22) to the bracket.
(e) Remove the LPC buffer air valve (1) from the engine.
(f) Remove the gasket (13) and discard it.
(g) Remove the seal (15) and discard it.

END OF PRE SB C-75-00-0022A (Initial Engine Configuration)

POST SB C-75-00-0022A (LPC Cabin Odor Configuration)

(4) Remove the LPC buffer air valve (1) from the tube (AP22), duct (AP32) and tube (AA25) as follows:

LPC Buffer Air Valve ** 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) Disconnect the tube (AA25) from the LPC buffer air valve (1).
(b) Disconnect the manifold (AA37) from the LPC buffer air valve (1).
(c) Remove the three nuts (16) and the three bolts (11).
(d) Remove the coupling (14) from the duct (AP32) and the LPC buffer air valve (1).
(e) Loosen the two bolts (12) and the clamp that attach the tube (AP22) to the bracket.
(f) Remove the LPC buffer air valve (1) from the engine.
(g) Remove the gasket (13) and discard it.
(h) Remove the seal (15) and discard it.

END OF POST SB C-75-00-0022A (LPC Cabin Odor Configuration)

(5) Installation of the protection covers:

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

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

[Rev.10 from 2021] 2026.04.01 13:02:06 UTC