Removal of the Overpressure Valve

TASK 36-11-53-000-802-A
Removal of the Overpressure Valve

WARNING: MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.

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.

WARNING: ALWAYS USE APPLICABLE GLOVES TO TOUCH HOT PARTS. HOT PARTS CAN CAUSE INJURY TO PERSONS.

WARNING: WEAR APPLICABLE PERSONAL PROTECTIVE EQUIPMENT (PPE) WHEN YOU DO THIS TASK. BEFORE YOU USE PPE, READ, UNDERSTAND AND OBEY ALL INSTRUCTIONS FOR ITS USE. THESE INSTRUCTIONS INCLUDE INSTRUCTIONS FROM THE MANUFACTURER, YOUR EMPLOYER AND GOVERNMENT REGULATIONS. YOU CAN GET INJURED IF YOU DO NOT USE PPE. GET INSTRUCTIONS FROM YOUR EMPLOYER ON WHICH PPE IS NECESSARY.

ZONE: 454
ZONE: 464
FIN: 7115HM1 ** ON A/C NOT FOR ALL
FIN: 7115HM2 ** 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 2M (6 FT) - ADJUSTABLE
No specific	AR	COVER - PROTECTION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
454	HOT SECTION
464	HOT SECTION
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 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 36-11-49-000-822-A	Removal of the Environmental Control System (ECS) Ducts
TASK 36-11-49-000-824-A	Removal of the Environmental Control System (ECS) Interface Duct
TASK 49-00-00-860-009-A	APU Shutdown by External Power (131-9(A))
TASK 49-00-00-860-009-A-01	APU Shutdown by Batteries (131-9(A))
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
Overpressure Valve

3. Job Set-up
Subtask 36-11-53-861-057-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002) or (Ref. AMM TASK 24-41-00-861-002).

Subtask 36-11-53-941-058-A ** ON A/C NOT FOR ALL

B. Safety Precautions
(1) Make sure that the engine 1(2) shut down occured not less than 5 minutes before you do this procedure.
(2) On AIR COND panel 30VU:
(a) Make sure that the ENG 1(2) BLEED pushbutton switch is released (OFF legend on).
(b) Make sure that the APU BLEED pushbutton switch is released (ON legend off).
(c) Put a WARNING NOTICE(S) in position to tell persons not to operate the pneumatic system.
(3) On the ENG panel 115VU:
- put a WARNING NOTICE(S) to tell persons not to start the engine 1(2).
(4) On the HP ground connector:
(a) Put a WARNING NOTICE(S) in position to tell persons not to pressurize the pneumatic system.
(5) On the ENG section of the maintenance panel 50VU:
- make sure that the ON legend of the ENG/FADEC GND PWR 1(2) pushbutton switch is off,
- put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 36-11-53-865-058-A ** ON A/C NOT FOR ALL

C. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR BLEED/ENG 2/MONG	3HA2	D12
49VU	AIR BLEED/ENG 1/CTL	2HA1	D11
122VU	AIR BLEED/ENG 1/MONG	3HA1	Z23
122VU	AIR BLEED/ENG 2/CTL	2HA2	Z22

Subtask 36-11-53-010-064-A ** ON A/C NOT FOR ALL

D. 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 36-11-53-040-057-A ** ON A/C NOT FOR ALL

E. 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 36-11-53-010-065-A ** ON A/C NOT FOR ALL

F. 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 2M (6 FT) - ADJUSTABLE in position below the fan cowl doors.

4. Procedure
Subtask 36-11-53-020-056-A ** ON A/C NOT FOR ALL

A. Removal of the Overpressure Valve
(1) If you use the APU to energize the electrical circuits, stop the APU:

For GTCP 36-300 APU (Ref. AMM D/O 49-00-00-86)
For APS 3200 (Ref. AMM D/O 49-00-00-86)
For 131-9(A) APU (Ref. AMM TASK 49-00-00-860-009).

(2) In the cockpit, on the SD bleed page:
(a) Make sure that the pressure and the temperature of the bleed-air duct system are in ambient conditions.

WARNING: MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.

WARNING: DO NOT TOUCH THE UNIT UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

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

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

(3) If necessary, loosen the ECS ducts to allow the clearance during the removal of the overpressure valve (1) (Ref. AMM TASK 36-11-49-000-822).
(4) Remove the three link assemblies from the interface duct assembly (Ref. AMM TASK 36-11-49-000-824).
(5) Hold the overpressure valve (1) and remove the V-band coupling (2) that attaches the overpressure valve (1) to the interface duct assembly.
(6) Hold the overpressure valve (1) and remove the V-band coupling (2) that attaches the overpressure valve (1) to the starter duct assembly.
(7) Remove the overpressure valve (1) and the seals (3) from the engine.
(8) Examine the seals (3) for damage:
(a) If you find damage, discard the seals (3).
(b) If there is no damage, keep the seals (3) for the installation procedure.
(9) Install COVER - PROTECTION on the overpressure valve (1), the interface duct assembly and the starter duct assembly.
(10) Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.04.01 01:13:18 UTC