Removal of the Buffer Air Valve Pressure Sensor [PW11]

TASK 75-26-22-000-801-A
Removal of the Buffer Air Valve Pressure Sensor

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: 4057KS ** 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	AR	COVER - PROTECTION
No specific	AR	PLIERS - JAWED, SOFT

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
Buffer Air Valve Pressure Sensor

3. Job Set-up
Subtask 75-26-22-941-050-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 75-26-22-010-050-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 75-26-22-040-050-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 75-26-22-010-051-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
Subtask 75-26-22-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Buffer Air Valve Pressure Sensor
(1) Find the buffer air valve pressure sensor (1) located on the Compressor Intermediate Case (CIC) bulkhead at approximately the 3 o'clock position.
(2) Remove the sensor (1) from the CIC bulkhead as follows:
(a) Disconnect the wiring harness (W04) connector (P69) from the sensor (1) with the PLIERS - JAWED, SOFT.
(b) Disconnect the tube (AS41).

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.

1 Disconnect the tube (AS41) from the sensor (1).
(c) Loosen the two bolts (2).

NOTE: It is not necessary to remove the bolts (2) completely.

(d) Remove the sensor (1) from the CIC bulkhead.
(3) Installation of 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 13:02:12 UTC