Removal of the Buffer Air Check Valve [PW11]

TASK 75-26-03-000-801-A
Removal of the Buffer Air Check Valve

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

FIN: 4051EM ** 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
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 71-00-00-860-833-A	Procedure to Prevent Engine Motoring
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
Buffer Air Check Valve

3. Job Set-up
Subtask 75-26-03-941-050-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 75-26-03-010-050-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

Subtask 75-26-03-040-050-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 75-26-03-010-051-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
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 75-26-03-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Buffer Air Check Valve
(1) Find the buffer air check valve (6) attached to the duct (AP34) and duct (AP33) (3) at approximately the 2 o'clock position.
(2) Remove the buffer air check valve (6) and duct (AP33) (3) from the Compressor Intermediate Case (CIC) and duct (AP34) as follows:
(a) Remove the coupling (5) from the duct (AP34) and duct (AP33) (3).
(b) Remove the five bolts (4).
(c) Remove the duct (AP33) (3) from the CIC.
(d) Remove and discard the gasket (2).
(e) Remove the buffer air check valve (6) from the duct (AP34).
(f) Remove and discard the two seals (1).
(3) 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 COVER - PROTECTION as necessary to prevent damage to the engine.

[Rev.10 from 2021] 2026.04.01 13:09:04 UTC