Removal of the Assembly of the APU Bleed Check-Valve
TASK 36-12-51-000-002-A
Removal of the Assembly of the APU Bleed Check-Valve
Removal of the Assembly of APU Bleed Check-Valve
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 36-12-51-865-056-A
Subtask 36-12-51-020-056-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 01:15:37 UTC
Removal of the Assembly 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.
WARNING:
ALWAYS USE APPLICABLE GLOVES TO TOUCH HOT PARTS. HOT PARTS CAN CAUSE INJURY TO PERSONS.
WARNING:
BE CAREFUL WHEN THE DUCTS ARE DISCONNECTED THE TEMPERATURE OF THE EXHAUST GASES FROM THE OPEN ENDS OF THE DISCONNECTED DUCTS CAN BE AS HIGH AS 270 DEG.C (518 DEG.F). THE HOT GASES CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.
CAUTION:
BE VERY CAREFUL WHEN YOU DO WORK ON OR NEAR THE AIR-CONDITIONING DUCTS. THE DUCTS ARE MADE OF THIN MATERIAL AND YOU CAN EASILY BREAK THEM.
CAUTION:
DO NOT PUT YOUR WEIGHT ON THE DUCTS. IT IS VERY EASY TO BREAK THEM.
1. Reason for the JobRemoval of the Assembly of APU Bleed Check-Valve
NOTE: If it is necessary to remove only the APU bleed check-valve and not the complete assembly:
2. Job Set-up Information- Do the procedure Removal of the APU bleed check-valve (Ref. TASK 36-12-51-000-00100).
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE |
| No specific | AR | PLUG - BLANKING |
| No specific | AR | SAFETY CLIP - CIRCUIT BREAKER |
| No specific | AR | WARNING NOTICE(S) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 150 | AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT |
| 190 | BELLY FAIR, AIR CONDITIONING & HYD COMPT |
| 211 | COCKPIT |
| 151CW, 151SW, 197BB | |
| 151BW, 151RW, 197KB |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 21-43-52-000-001-A | Removal of the Pressure Regulating Valve - Aft Cargo-Compartment Heating |
| TASK 25-55-11-000-001-A | Removal of the Aft Cargo-Compartment Partition at FR47 |
| TASK 25-55-11-000-003-A | Removal of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59 |
| TASK 29-00-00-910-004-A | General Rules for Removal and Installation Procedures in the Hydraulic Systems |
| TASK 36-12-51-200-001-A | Remove and Check the Auxiliary Power Unit (APU) Bleed Check-Valve for Condition |
| TASK 36-22-17-000-001-A | Removal 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 53-35-13-000-002-A | Removal of the Quick-Release Access Panels from the Belly Fairing Structure |
Subtask 36-12-51-865-056-A
A. Open, safety and tag this(these) circuit breaker(s):
Subtask 36-12-51-860-053-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | AIR BLEED/ENG 1/CTL | 3HA1 | D12 |
| 49VU | AIR BLEED/ENG 1/MONG | 2HA1 | D11 |
| ** ON A/C ALL | |||
| 49VU | AIR BLEED/X FEED/VALVE/BAT | 2HV | D13 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | AIR BLEED/ENG 2/MONG | 3HA2 | D12 |
| 49VU | AIR BLEED/ENG 1/CTL | 2HA1 | D11 |
| ** ON A/C NOT FOR ALL | |||
| 122VU | AIR BLEED/ENG 2/CTL | 3HA2 | Z23 |
| 122VU | AIR BLEED/ENG 2/MONG | 2HA2 | Z22 |
| ** ON A/C ALL | |||
| 122VU | AIR BLEED/X FEED VALVE/NORM | 1HV | Z20 |
| ** ON A/C NOT FOR ALL | |||
| 122VU | AIR BLEED/ENG 1/MONG | 3HA1 | Z23 |
| 122VU | AIR BLEED/ENG 2/CTL | 2HA2 | Z22 |
B. Aircraft Maintenance Configuration
(1) Put the WARNING NOTICE(S) in position:
Subtask 36-12-51-010-052-A ** ON A/C NOT FOR ALL (1) Put the WARNING NOTICE(S) in position:
- in the cockpit on the Engine Control Panel 115VU to tell persons not to start the engine(s),
- in the cockpit on the AIR COND Overhead Control Panel 30VU to tell persons not to push in the APU BLEED pushbutton switch,
- on the HP ground connector to tell persons not to pressurize the pneumatic system.
C. Get Access
(1) Remove access panel 197BB (Ref. AMM TASK 53-35-13-000-002).
(2) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(3) In the aft cargo compartment, remove the sidewall panel:
(a) If installed, remove sidewall panel 151CW (Ref. AMM TASK 25-55-11-000-003), or
(b) If installed, remove sidewall panel 151SW (Ref. AMM TASK 25-55-11-000-003).
Subtask 36-12-51-860-053-B ** ON A/C NOT FOR ALL (1) Remove access panel 197BB (Ref. AMM TASK 53-35-13-000-002).
(2) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(3) In the aft cargo compartment, remove the sidewall panel:
(a) If installed, remove sidewall panel 151CW (Ref. AMM TASK 25-55-11-000-003), or
(b) If installed, remove sidewall panel 151SW (Ref. AMM TASK 25-55-11-000-003).
D. Aircraft Maintenance Configuration
(1) Put the WARNING NOTICE(S) in position:
Subtask 36-12-51-010-052-C ** ON A/C NOT FOR ALL (1) Put the WARNING NOTICE(S) in position:
- in the cockpit on the Engine Control Panel 115VU to tell persons not to start the engine(s),
- in the cockpit on the AIR COND Overhead Control Panel 30VU to tell persons not to push in the APU BLEED pushbutton switch,
- on the HP ground connector to tell persons not to pressurize the pneumatic system.
E. Get Access
(1) Remove access panel 197KB (Ref. AMM TASK 53-35-13-000-002).
(2) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(3) In the aft cargo compartment:
(a) Remove sidewall panel 151RW (Ref. AMM TASK 25-55-11-000-003).
(b) Remove partition panel 151BW (Ref. AMM TASK 25-55-11-000-001).
4. Procedure(1) Remove access panel 197KB (Ref. AMM TASK 53-35-13-000-002).
(2) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(3) In the aft cargo compartment:
(a) Remove sidewall panel 151RW (Ref. AMM TASK 25-55-11-000-003).
(b) Remove partition panel 151BW (Ref. AMM TASK 25-55-11-000-001).
Subtask 36-12-51-020-056-A ** ON A/C NOT FOR ALL
A. Removal of the Assembly of the APU Bleed Check-Valve
(1) If necessary, remove the hydraulic pipe line (Ref. AMM TASK 29-00-00-910-004).
(3) Remove the bolts (22) and the washers (21) from the bracket (20).
(4) Loosen the screw of the clamp (23).
(5) Remove the clamp (23) from the bleed air duct (9).
(6) Loosen the nut (4).
(7) Remove the nut (4), washer (5), bonding strap (8) and bolt (10) from the bleed air duct (2).
(8) Safety the bonding strap (8) on the bleed air duct (9).
(9) Loosen the nuts (7).
(10) Remove the nuts (7), the washers (6) and the bolts (1) from the bleed air ducts (2) and (9).
(11) Remove the connecting rods (3) from the bleed air ducts (2) and (9).
(13) Carefully pull the bleed air duct (2) to get access to the APU bleed-check-valve assembly (14).
(14) Remove the clamp (18) from the bleed air duct (2).
(16) Carefully pull the bleed air duct (11) to get access to the APU bleed-check-valve assembly (14).
(17) Remove the clamp (12) from the bleed air duct (11).
(18) Remove the nuts (17) and the washers (16) from the structure.
(19) Hold the APU bleed-check-valve assembly (14) and remove the bolts (13).
(20) Remove the APU bleed-check-valve assembly (14):
(a) Make sure that the parts of the APU bleed-check-valve assembly (14) (the flap, the shaft and the spring) are not missing (Ref. AMM TASK 36-12-51-200-001).
(b) If the part(s) is (are) missing, do the step that follow before you install the new APU bleed-check-valve assembly:
1 Do an inspection of the APU bleed-air system and the air conditioning system to find the missing parts.
(21) Remove the seal (15).
(22) Put the PLUG-BLANKING in each disconnected line end.
Subtask 36-12-51-020-056-B ** ON A/C NOT FOR ALL (1) If necessary, remove the hydraulic pipe line (Ref. AMM TASK 29-00-00-910-004).
CAUTION:
REMOVE OR INSTALL THE SENSING ELEMENTS CAREFULLY. DO NOT TWIST, BEND OR CAUSE KINKS IN THE SENSING ELEMENTS. IF YOU DO, YOU CAN CAUSE DAMAGE TO THEM.
(2) Remove the APU overheat sensing-elements (19) from the bleed air duct (2) (Ref. AMM TASK 36-22-17-000-001). (3) Remove the bolts (22) and the washers (21) from the bracket (20).
(4) Loosen the screw of the clamp (23).
(5) Remove the clamp (23) from the bleed air duct (9).
(6) Loosen the nut (4).
(7) Remove the nut (4), washer (5), bonding strap (8) and bolt (10) from the bleed air duct (2).
(8) Safety the bonding strap (8) on the bleed air duct (9).
(9) Loosen the nuts (7).
(10) Remove the nuts (7), the washers (6) and the bolts (1) from the bleed air ducts (2) and (9).
(11) Remove the connecting rods (3) from the bleed air ducts (2) and (9).
CAUTION:
SOME PRESSURE CAN STAY IN THE DUCTING. THE PRESSURE WILL DECREASE WHEN YOU RELEASE THE CLAMPS.
(12) Loosen the bolt of the clamp (18) installed on the bleed air duct (2) and the APU bleed-check-valve assembly (14).(13) Carefully pull the bleed air duct (2) to get access to the APU bleed-check-valve assembly (14).
(14) Remove the clamp (18) from the bleed air duct (2).
CAUTION:
SOME PRESSURE CAN STAY IN THE DUCTING. THE PRESSURE WILL DECREASE WHEN YOU RELEASE THE CLAMPS.
(15) Loosen the bolt of the clamp (12) installed on the bleed air duct (11) and the APU bleed-check-valve assembly (14).(16) Carefully pull the bleed air duct (11) to get access to the APU bleed-check-valve assembly (14).
(17) Remove the clamp (12) from the bleed air duct (11).
(18) Remove the nuts (17) and the washers (16) from the structure.
(19) Hold the APU bleed-check-valve assembly (14) and remove the bolts (13).
(20) Remove the APU bleed-check-valve assembly (14):
(a) Make sure that the parts of the APU bleed-check-valve assembly (14) (the flap, the shaft and the spring) are not missing (Ref. AMM TASK 36-12-51-200-001).
(b) If the part(s) is (are) missing, do the step that follow before you install the new APU bleed-check-valve assembly:
1 Do an inspection of the APU bleed-air system and the air conditioning system to find the missing parts.
(21) Remove the seal (15).
(22) Put the PLUG-BLANKING in each disconnected line end.
A. Removal of the Assembly of the APU Bleed Check-Valve
(1) If necessary, remove the hydraulic pipe line (Ref. AMM TASK 29-00-00-910-004).
(3) Remove the bolts (25) and the washers (24) from the bracket (23).
(5) Disconnect the bleed air duct (2) from the Pressure Regulating Valve (PRV) (20).
(6) Remove the clamp (21).
(7) Remove and discard the O-ring (22).
(8) If necessary, remove the PRV (20) (Ref. AMM TASK 21-43-52-000-001).
(9) Loosen the screw of the clamp (26).
(10) Remove the clamp (26) from the bleed air duct (9).
(11) Loosen the nut (4).
(12) Remove the nut (4), washer (5), bonding strap (8) and bolt (10) from the bleed air duct (2).
(13) Safety the bonding strap (8) on the bleed air duct (9).
(14) Loosen the nuts (7).
(15) Remove the nuts (7), the washers (6) and the bolts (1) from the bleed air ducts (2) and (9).
(16) Remove the connecting rods (3) from the bleed air ducts (2) and (9).
(18) Carefully pull the bleed air duct (2) to get access to the APU bleed-check-valve assembly (14).
(19) Remove the clamp (18) from the bleed air duct (2).
(21) Carefully pull the bleed air duct (11) to get access to the APU bleed-check-valve assembly (14).
(22) Remove the clamp (12) from the bleed air duct (11).
(23) Remove the nuts (17) and the washers (16) from the structure.
(24) Hold the APU bleed-check-valve assembly (14) and remove the bolts (13).
(25) Remove the APU bleed-check-valve assembly (14):
(a) Make sure that the parts of the APU bleed-check-valve assembly (14) (the flap, the shaft and the spring) are not missing (Ref. AMM TASK 36-12-51-200-001).
(b) If the part(s) is (are) missing, do the step that follow before you install the new APU bleed-check-valve assembly:
1 Do an inspection of the APU bleed-air system and the air conditioning system to find the missing parts.
(26) Remove the seal (15).
(27) Put the PLUG-BLANKING in each disconnected line end.
(1) If necessary, remove the hydraulic pipe line (Ref. AMM TASK 29-00-00-910-004).
CAUTION:
REMOVE OR INSTALL THE SENSING ELEMENTS CAREFULLY. DO NOT TWIST, BEND OR CAUSE KINKS IN THE SENSING ELEMENTS. IF YOU DO, YOU CAN CAUSE DAMAGE TO THEM.
(2) Remove the APU overheat sensing-elements (19) from the bleed air duct (2) (Ref. AMM TASK 36-22-17-000-001). (3) Remove the bolts (25) and the washers (24) from the bracket (23).
CAUTION:
SOME PRESSURE CAN STAY IN THE DUCTING. THE PRESSURE WILL DECREASE WHEN YOU RELEASE THE CLAMPS.
(4) Loosen the screw of the clamp (21).(5) Disconnect the bleed air duct (2) from the Pressure Regulating Valve (PRV) (20).
(6) Remove the clamp (21).
(7) Remove and discard the O-ring (22).
(8) If necessary, remove the PRV (20) (Ref. AMM TASK 21-43-52-000-001).
(9) Loosen the screw of the clamp (26).
(10) Remove the clamp (26) from the bleed air duct (9).
(11) Loosen the nut (4).
(12) Remove the nut (4), washer (5), bonding strap (8) and bolt (10) from the bleed air duct (2).
(13) Safety the bonding strap (8) on the bleed air duct (9).
(14) Loosen the nuts (7).
(15) Remove the nuts (7), the washers (6) and the bolts (1) from the bleed air ducts (2) and (9).
(16) Remove the connecting rods (3) from the bleed air ducts (2) and (9).
CAUTION:
SOME PRESSURE CAN STAY IN THE DUCTING. THE PRESSURE WILL DECREASE WHEN YOU RELEASE THE CLAMPS.
(17) Loosen the bolt of the clamp (18) installed on the bleed air duct (2) and the APU bleed-check-valve assembly (14).(18) Carefully pull the bleed air duct (2) to get access to the APU bleed-check-valve assembly (14).
(19) Remove the clamp (18) from the bleed air duct (2).
CAUTION:
SOME PRESSURE CAN STAY IN THE DUCTING. THE PRESSURE WILL DECREASE WHEN YOU RELEASE THE CLAMPS.
(20) Loosen the bolt of the clamp (12) installed on the bleed air duct (11) and the APU bleed-check-valve assembly (14).(21) Carefully pull the bleed air duct (11) to get access to the APU bleed-check-valve assembly (14).
(22) Remove the clamp (12) from the bleed air duct (11).
(23) Remove the nuts (17) and the washers (16) from the structure.
(24) Hold the APU bleed-check-valve assembly (14) and remove the bolts (13).
(25) Remove the APU bleed-check-valve assembly (14):
(a) Make sure that the parts of the APU bleed-check-valve assembly (14) (the flap, the shaft and the spring) are not missing (Ref. AMM TASK 36-12-51-200-001).
(b) If the part(s) is (are) missing, do the step that follow before you install the new APU bleed-check-valve assembly:
1 Do an inspection of the APU bleed-air system and the air conditioning system to find the missing parts.
(26) Remove the seal (15).
(27) Put the PLUG-BLANKING in each disconnected line end.
Assembly of the APU Bleed Check-Valve