DOC AIRBUS | AMM A320FPressurization of the Hydraulic Reservoirs with the Auxiliary Power Unit (APU)
TASK 29-14-00-614-002-A-01
Pressurization of the Hydraulic Reservoirs with the Auxiliary Power Unit (APU)
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 29-14-00-860-063-A
Subtask 29-14-00-614-060-A
Subtask 29-14-00-865-073-A
[Rev.10 from 2021]
2026.04.01 00:24:08 UTC
Pressurization of the Hydraulic Reservoirs with the Auxiliary Power Unit (APU)
WARNING:
MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.
ZONE: 195
1. Reason for the JobNOTE: This task is applicable to pressurize the hydraulic reservoir with a maximum of air pressure to approximately 1.65 bar (24 psi).
NOTE: This task is not applicable to Aircrafts equipped with DOWTY RAT. The DOWTY RAT needs a minimum reservoir pressure of 3.1 bar absolute (45 psi A).
NOTE: There are alternative methods for this procedure. This task gives one of the methods. For the other methods, refer to the other tasks in this page block.
2. Job Set-up InformationA. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | SAFETY CLIP - CIRCUIT BREAKER |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 195 | HYDRAULIC COMPT AND FAIRINGS |
| 196BB, 197FB |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 12-12-29-611-001-A | Fill the Hydraulic Fluid Reservoir with a Hand Pump |
| TASK 12-12-29-611-002-A | Fill the Hydraulic Fluid Reservoir with a Hydraulic Service Cart |
| TASK 24-41-00-861-002-A-01 | Energize the Aircraft Electrical Circuits from the APU |
| TASK 24-41-00-862-002-A-01 | De-energize the Aircraft Electrical Circuits Supplied from the APU |
| TASK 31-60-00-860-001-A | EIS Start Procedure |
| TASK 31-60-00-860-002-A | EIS Stop Procedure |
| TASK 32-12-00-010-001-A | Open the Main Gear Doors for Access |
| TASK 32-12-00-410-001-A | Close the Main Gear Doors after Access |
| TASK 36-12-00-860-001-A | Pressurization of the Bleed System with the APU |
Subtask 29-14-00-860-063-A
A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits from the APU (Ref. AMM TASK 24-41-00-861-002).
(2) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(3) On the ECAM control panel on the center pedestal, push the HYD pushbutton switch (P/BSW). Make sure that the ECAM lower DU shows the HYD page.
(4) Make sure that the ECAM does not show these warnings:
Subtask 29-14-00-010-064-A (1) Energize the aircraft electrical circuits from the APU (Ref. AMM TASK 24-41-00-861-002).
(2) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(3) On the ECAM control panel on the center pedestal, push the HYD pushbutton switch (P/BSW). Make sure that the ECAM lower DU shows the HYD page.
(4) Make sure that the ECAM does not show these warnings:
- Low fluid level in the Green/Yellow/Blue reservoirs.
- Low air pressurization indication is shown if the pressure is less than 1.5 +0.1 bar or -0.1 bar (21.8 +1.5 psi or -1.5 psi).
B. Get Access
(1) Open access doors 197FB 196BB.
(2) Open one of the doors of the Main Landing Gear (MLG) (Ref. AMM TASK 32-12-00-010-001).
Subtask 29-14-00-865-074-A (1) Open access doors 197FB 196BB.
(2) Open one of the doors of the Main Landing Gear (MLG) (Ref. AMM TASK 32-12-00-010-001).
C. Open, safety and tag these circuit breakers in this sequence:
Subtask 29-14-00-865-071-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 122VU | ANTI ICE/PROBES/1/TAT | 1DA1 | Z12 |
| 122VU | ANTI ICE/PROBES/2/TAT | 1DA2 | Y15 |
| 49VU | ANTI ICE/PROBES/PITOT/1 | 3DA1 | D02 |
| 122VU | ANTI ICE/PROBES/2/PITOT | 3DA2 | Y14 |
| 122VU | ANTI ICE/PROBES/3/PITOT | 3DA3 | Z16 |
| 49VU | ANTI ICE/PROBES/AOA/1 | 4DA1 | D04 |
| 122VU | ANTI ICE/PROBES/2/AOA | 4DA2 | Y13 |
| 122VU | ANTI ICE/PROBES/3/AOA | 4DA3 | Z15 |
| 122VU | ANTI ICE/PROBES/1/STATIC | 5DA1 | Z13 |
| 122VU | ANTI ICE/PROBES/2/STATIC | 5DA2 | Y11 |
| 122VU | ANTI ICE/PROBES/3/STATIC | 5DA3 | Z14 |
D. Open, safety and tag this(these) circuit breaker(s):
Subtask 29-14-00-865-072-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | ENGINE/2/FADEC A/AND EIU 2 | 2KS2 | A05 |
| 49VU | ENGINE/1/FADEC A/AND EIU 1 | 2KS1 | A04 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG2/FADEC B | 4KS2 | Q40 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG1/FADEC B/AND EIU 1 | 4KS1 | R41 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG2/FADEC B/AND EIU2 | 4KS2 | Q40 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG2/FADEC B/AND EIU2 | 4KS2 | R41 |
| 121VU | ENGINE/ENG1/FADEC B/AND EIU 1 | 4KS1 | R40 |
E. Make sure that this(these) circuit breaker(s) is(are) closed:
4. Procedure| PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 121VU | APU/APU/CTL | 2KD | L42 |
Subtask 29-14-00-614-060-A
A. Pressurization of the Hydraulic Reservoirs with the APU
5. Close-up| ACTION | RESULT |
|---|---|
| 1.Pressurize the Bleed System with the APU (Ref. AMM TASK 36-12-00-860-001). NOTE: The APU must work in the pressurization condition:
| |
| 2.On ENG panel 115VU, put the ENG MODE CRANK/NORM/IGN/START selector switch in the CRANK position. | The APU boosts the air bleed pressure to 1.65 bar (24 psi) approx. in less than 30 s:
|
| 3.On ENG panel 115VU, put the ENG MODE CRANK/NORM/IGN/START selector switch in the NORM position. |
|
| 4.Stop pressurizing the Bleed System with the APU (Ref. AMM TASK 36-12-00-860-001). | |
Subtask 29-14-00-865-073-A
A. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 29-14-00-865-075-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | ENGINE/2/FADEC A/AND EIU 2 | 2KS2 | A05 |
| 49VU | ENGINE/1/FADEC A/AND EIU 1 | 2KS1 | A04 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG2/FADEC B | 4KS2 | Q40 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG1/FADEC B/AND EIU 1 | 4KS1 | R41 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG2/FADEC B/AND EIU2 | 4KS2 | Q40 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | ENGINE/ENG2/FADEC B/AND EIU2 | 4KS2 | R41 |
| 121VU | ENGINE/ENG1/FADEC B/AND EIU 1 | 4KS1 | R40 |
B. Remove the safety clips and tags and close these circuit breakers in this sequence:
Subtask 29-14-00-410-063-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 122VU | ANTI ICE/PROBES/3/STATIC | 5DA3 | Z14 |
| 122VU | ANTI ICE/PROBES/2/STATIC | 5DA2 | Y11 |
| 122VU | ANTI ICE/PROBES/1/STATIC | 5DA1 | Z13 |
| 122VU | ANTI ICE/PROBES/3/AOA | 4DA3 | Z15 |
| 122VU | ANTI ICE/PROBES/2/AOA | 4DA2 | Y13 |
| 49VU | ANTI ICE/PROBES/AOA/1 | 4DA1 | D04 |
| 122VU | ANTI ICE/PROBES/3/PITOT | 3DA3 | Z16 |
| 122VU | ANTI ICE/PROBES/2/PITOT | 3DA2 | Y14 |
| 49VU | ANTI ICE/PROBES/PITOT/1 | 3DA1 | D02 |
| 122VU | ANTI ICE/PROBES/2/TAT | 1DA2 | Y15 |
| 122VU | ANTI ICE/PROBES/1/TAT | 1DA1 | Z12 |
C. Close Access
(1) Close access doors 197FB 196BB.
(2) Close the doors of the MLG (Ref. AMM TASK 32-12-00-410-001).
Subtask 29-14-00-860-064-A (1) Close access doors 197FB 196BB.
(2) Close the doors of the MLG (Ref. AMM TASK 32-12-00-410-001).
D. Aircraft Maintenance Configuration
(1) Do the EIS stop procedure
(Ref. AMM TASK 31-60-00-860-002).
(2) De-energize the aircraft electrical circuits from the APU (Ref. AMM TASK 24-41-00-862-002).
(1) Do the EIS stop procedure
(Ref. AMM TASK 31-60-00-860-002).
(2) De-energize the aircraft electrical circuits from the APU (Ref. AMM TASK 24-41-00-862-002).