Installation of the Buffer Air Check Valve [PW11]

TASK 75-26-03-400-801-A
Installation 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.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

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	1	MALLET - SOFT FACE
No specific	Torque wrench: range to between 90 and 75 lbf.in (1.02 and 0.85 m.daN )
No specific	Torque wrench: range to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.P03-001)	lubricant, aircraft turbine engine
(Material No.P05-395)	beeswax
(Material No.P05-396)	Paraffin wax blend (PMC 9462)
(Material No.P06-054)	Antigalling Compound

C. 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

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
1	SEAL	EIPC 75-26-03-01-090
2	GASKET	EIPC 75-26-03-01-110

E. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-720-811-A	Test No. 3A - Idle Power Test
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 71-13-00-410-802-A	Closing of the Fan Cowl Doors
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 Check Valve

3. Job Set-up
Subtask 75-26-03-941-051-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Make sure that you did the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).

Subtask 75-26-03-010-052-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 75-26-03-040-051-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 75-26-03-010-053-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
(2) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.

4. Procedure
Subtask 75-26-03-420-050-A ** ON A/C NOT FOR ALL

A. Installation of the Buffer Air Check 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) Install the buffer air check valve (6) on the duct (AP33) (3) and duct (AP34) as follows:
(a) Apply P05-396Paraffin wax blend (PMC 9462) or beeswax (Material No.P05-395) to the two new EIPC 75-26-03-01-090 SEAL (1).
(b) Install the two seals (1) on the buffer air check valve (6).
(c) Install the buffer air check valve (6) into the duct (AP34).
(d) Install the new EIPC 75-26-03-01-110 GASKET (2) on the duct (AP33) (3) with P05-396Paraffin wax blend (PMC 9462) or beeswax (Material No.P05-395) .
(e) Apply Antigalling Compound (Material No.P06-054) to the threads of the five bolts (4).

NOTE: For new or refurbished bolts or nuts with baked-on lubricant, do not do the wet application.

(f) Install the duct (AP33) (3) on the Compressor Intermediate Case (CIC) with the five bolts (4) finger-tight.
(g) Apply P03-001lubricant, aircraft turbine engine to the threads of the coupling (5).
(h) Install the coupling (5) on the duct (AP33) (3) and duct (AP34).
(i) TORQUE the coupling (5) to between 90 and 75 lbf.in (1.02 and 0.85 m.daN )

.
(j) Tap the coupling (5) with a MALLET - SOFT FACE.
(k) TORQUE the coupling (5) again to between 90 and 75 lbf.in (1.02 and 0.85 m.daN )

.
(l) TORQUE the five bolts (4) to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )

5. Close-up
Subtask 75-26-03-410-050-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 75-26-03-440-050-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 75-26-03-410-051-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 access platform(s).
(3) Remove the WARNING NOTICE(S).

Subtask 75-26-03-720-050-A ** ON A/C NOT FOR ALL

D. Test(s)
(1) Do the test No. 3 - Idle power test (Ref. AMM TASK 71-00-00-720-811).

[Rev.10 from 2021] 2026.04.01 03:13:18 UTC