Deactivation of the APU Bleed Check-Valve

TASK 36-12-00-040-801-A
Deactivation of the APU Bleed Check-Valve

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

FIN: 7260HM ** ON A/C NOT FOR ALL

1. Reason for the Job
MMEL 36-22-03A
APU LEAK DETECTION LOOP
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.5 and 0.4 m.daN (44.25 and 35.40 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
151CW
151SW, 197BB
197KB

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
10	BLANKING CAP	AIPC 36-12-03-28-260

D. Referenced Information

REFERENCE	DESIGNATION
TASK 12-33-21-618-001-A-02	Pre-conditioning with the APU
TASK 36-22-17-000-001-A	Removal of the APU Overheat Sensing-Elements
TASK 36-22-17-400-001-A	Installation of the APU Overheat Sensing-Elements
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
AIPC 36-12-03-28
APU Bleed Check-Valve - Blanking Cap ** ON A/C NOT FOR ALL
APU Bleed Check-Valve - Blanking Cap ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 36-12-00-860-096-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Put the WARNING NOTICE(S) in position:

In the cockpit, on engine control panel 115VU, to tell persons not to start the engine(s)
In the cockpit, on AIR COND overhead control panel 30VU, to tell persons not to push the APU BLEED pushbutton switch
On the HP ground connector, to tell persons not to pressurize the pneumatic system.

Subtask 36-12-00-010-066-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position below access panel 197BB.
(2) Remove access panel 197BB.
(3) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) In the aft cargo compartment, remove the sidewall panel:
(a) If installed, remove sidewall panel 151CW, or
(b) If installed, remove sidewall panel 151SW.

Subtask 36-12-00-010-066-C ** ON A/C NOT FOR ALL

B. Get Access
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position below access panel 197KB.
(2) Remove access panel 197KB.
(3) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(4) In the aft cargo compartment, remove sidewall panel 151CW.

Subtask 36-12-00-865-089-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/X FEED/VALVE/BAT	2HV	D13
49VU	AIR BLEED/ENG 1/CTL	3HA1	D12
49VU	AIR BLEED/ENG 1/MONG	2HA1	D11
122VU	AIR BLEED/ENG 2/CTL	3HA2	Z23
122VU	AIR BLEED/ENG 2/MONG	2HA2	Z22
122VU	AIR BLEED/X FEED VALVE/NORM	1HV	Z20

4. Procedure
Subtask 36-12-00-020-063-A ** ON A/C NOT FOR ALL

A. Deactivation of the APU Bleed Check-Valve

NOTE: Refer to AIPC 36-12-03-28 for the AIPC 36-12-03-28-260 BLANKING CAP (10) of the APU bleed check-valve (6) to do the procedure.

(1) Disengage the overheat sensing elements that are near the APU bleed check-valve (6) from the ducts (9) and (4) (Ref. AMM TASK 36-22-17-000-001).
(2) Loosen the nut of the clamp (3) and remove the clamp (3).
(3) Loosen the nut of the clamp (8) and remove the clamp (8).
(4) Remove the nuts (2) and the washers (1).
(5) Hold the APU bleed check-valve (6) and remove the bolts (7).
(6) Remove the APU bleed check-valve (6) and the seal (5).
(7) Make sure that no parts of the APU bleed check-valve (6) are missing (flaps, shaft and spring) when you remove it. If part(s) is (are) missing:

Do an inspection of the APU bleed-air system and the air conditioning system to find this (these) parts before you install the blanking cap (10).

(8) Put the blanking cap (10) with the seal (5) in position.
(9) Install the bolts (7), washers (1) and nuts (2).
(10) Tighten the nuts (2).
(11) Install the clamps (3) and (8).
(12) TORQUE the nuts of the clamps (3) and (8) to between 0.5 and 0.4 m.daN (44.25 and 35.40 lbf.in )

.
(13) Attach the overheat sensing elements that are near the APU bleed check-valve (6) to the ducts (9) and (4) (Ref. AMM TASK 36-22-17-400-001).

Subtask 36-12-00-865-090-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR BLEED/X FEED/VALVE/BAT	2HV	D13
49VU	AIR BLEED/ENG 1/CTL	3HA1	D12
49VU	AIR BLEED/ENG 1/MONG	2HA1	D11
122VU	AIR BLEED/ENG 2/CTL	3HA2	Z23
122VU	AIR BLEED/ENG 2/MONG	2HA2	Z22
122VU	AIR BLEED/X FEED VALVE/NORM	1HV	Z20

Subtask 36-12-00-710-062-A ** ON A/C NOT FOR ALL

C. Leak Test of the Pneumatic Connections
(1) Do the ground air pre-conditioning with the APU (Ref. AMM TASK 12-33-21-618-001).
(2) Make sure that there are no leaks between the connections of the blanking cap (10) and the ducts (4) and (9).

5. Close-up
Subtask 36-12-00-410-066-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) Install access panel 197BB.
(3) In the aft cargo compartment, install the sidewall panel:
(a) If removed, install sidewall panel 151CW, or
(b) If removed, install sidewall panel 151SW.
(4) Close the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).

Subtask 36-12-00-410-066-C ** 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) Install access panel 197KB.
(3) In the aft cargo compartment, install sidewall panel 151CW.
(4) Close the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).

Subtask 36-12-00-860-098-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) Put the aircraft back to the serviceable condition.
(2) Remove the WARNING NOTICE(S).
(3) Remove the access platform(s).
(4) Make an entry in the logbook.

[Rev.10 from 2021] 2026.04.01 12:39:15 UTC