Installation of the Buffer Air Valve Pressure Sensor [PW11]

TASK 75-26-22-400-801-A
Installation 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
Use this procedure to install the buffer air valve pressure sensor.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	PLIERS - JAWED, SOFT
No specific	Torque wrench: range to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )
No specific	Torque wrench: range to between 110 and 100 lbf.in (1.24 and 1.13 m.daN )

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 71-13-00-410-802-A	Closing of the Fan Cowl Doors
TASK 73-21-00-710-807-A	Test No.6 - EEC Operation Test (Idle Test)
TASK 73-25-34-400-802-A	Installation of the Engine Interface Unit (EIU)
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-805-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
TASK 78-36-00-410-802-A	Closing of the Thrust Reverser Cowl-Doors
Buffer Air Valve Pressure Sensor

3. Job Set-up
Subtask 75-26-22-941-056-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Make sure that you did 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 75-26-22-010-052-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Make sure that the fan cowl doors are open (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 75-26-22-040-051-A ** ON A/C NOT FOR ALL

C. Deactivation of the Thrust Reverser System 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) Make sure that you did the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-805).

Subtask 75-26-22-010-053-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Make sure that the right thrust reverser cowl-door is open (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 75-26-22-420-050-A ** ON A/C NOT FOR ALL

A. Installation of the Buffer Air Valve Pressure Sensor

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

(1) Make sure that you remove the COVER - PROTECTION as necessary to prevent damage to the engine.
(2) Install the sensor (1) to the Compressor Intermediate Case (CIC) bulkhead as follows:
(a) Install the sensor (1) to the two bolts (2).
(b) TORQUE the bolts (2) to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )

.
(c) Connect the tube (AS41) to the sensor (1).

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.

(d) TORQUE the B-nut to between 110 and 100 lbf.in (1.24 and 1.13 m.daN )

.
(3) Connect the wiring harness (W04) connector (P69) to the sensor receptacle (J56) as follows:
(a) Examine, align and engage the connector.
(b) Push lightly inward on the connector while you tighten the coupling ring.
(c) Use the PLIERS - JAWED, SOFT to tighten the connector against the receptacle.
(d) Make sure that you can feel the ratchet feature.
(e) While you tighten, push the connector in and from side to side.
(f) Tighten the connector until the PLIERS - JAWED, SOFT slip on the connector ring.
(4) Examine the assembly for foreign objects, damage, and correct assembly.

5. Close-up
Subtask 75-26-22-410-050-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the right thrust reverser cowl-door (Ref. AMM TASK 78-36-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
462AR

Subtask 75-26-22-440-050-A ** ON A/C NOT FOR ALL

B. Do the reactivation of the thrust reverser system after maintenance (Ref. AMM TASK 78-30-00-440-805).

Subtask 75-26-22-410-051-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).
(3) Make sure that all the circuit breakers shown in the paragraph Procedure of the engine interface unit installation are closed. If they are not, close them in the recommended sequence
(Ref. AMM TASK 73-25-34-400-802)

Subtask 75-26-22-720-050-A ** ON A/C NOT FOR ALL

D. Test
(1) Do the test No.6 - EEC - Idle test (Ref. AMM TASK 73-21-00-710-807).

[Rev.10 from 2021] 2026.04.01 13:02:12 UTC