DOC AIRBUS | AMM A320FRemove and Replace HCU Pipes
TASK 29-13-49-920-801-A
Remove and Replace HCU Pipes
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Expendable Parts
D. Referenced Information
3. Job Set-up
Subtask 29-13-49-860-145-A ** ON A/C NOT FOR ALL
Subtask 29-13-49-020-136-A ** ON A/C NOT FOR ALL
Subtask 29-13-49-410-124-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 00:22:50 UTC
Remove and Replace HCU Pipes
WARNING:
OBEY THE HYDRAULIC SAFETY PROCEDURES.
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.
WARNING:
DO NOT GET HYDRAULIC FLUID ON YOUR SKIN, IN YOUR EYES OR IN YOUR MOUTH. HYDRAULIC FLUID IS POISONOUS AND CAN GO THROUGH YOUR SKIN AND INTO YOUR BODY. FLUSH HYDRAULIC FLUID FROM YOUR EYES, MOUTH OR SKIN WITH WATER. GET MEDICAL AID IF YOU GET HYDRAULIC FLUID IN YOUR EYES OR MOUTH.
CAUTION:
DO NOT LET HYDRAULIC FLUID FALL ON THE ENGINE. UNWANTED HYDRAULIC FLUID MUST BE REMOVED IMMEDIATELY WITH A CLEAN LINT FREE CLOTH. THE FLUID CAN CAUSE DAMAGE TO THE SURFACE PROTECTION AND TO SOME PARTS.
CAUTION:
USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT HYDRAULIC LINES ON UNIONS. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL LOOSEN OR TIGHTEN THE UNION TOO MUCH.
ZONE: 420
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 420 | ENG 2 PYLON BOX AND FORWARD FAIRING |
| 423AL, 447AL |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 6 | PIPE | AIPC 29-13-06-03-120 |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 20-23-22-910-001-A | Marking of the Unions after Application of Standard or Specific Tightening Torque |
| TASK 24-42-00-861-001-A | Energize the Ground Service Network from the External Power |
| TASK 24-42-00-862-001-A | De-energize the Ground Service Network Supplied from the External Power |
| TASK 29-00-00-910-002-A | Safety Procedures of the Hydraulic System |
| TASK 29-10-00-864-002-A | Depressurize the Yellow Hydraulic System |
| TASK 29-13-00-710-002-A | Operational Test of the Yellow Hydraulic System |
| TASK 29-14-00-614-001-A | Depressurization of the Hydraulic Reservoirs |
| TASK 29-14-00-614-002-A | Pressurization of the Hydraulic Reservoirs through the Ground Connector |
| TASK 29-14-00-614-002-A-01 | Pressurization of the Hydraulic Reservoirs with the Auxiliary Power Unit (APU) |
| TASK 54-52-11-000-002-B | Removal of the Access Panels |
| TASK 54-52-11-400-002-B | Installation of the Access Panels |
| TASK 71-13-11-000-010-A | Removal of the Left Fan Cowl 437AL(447AL). |
| TASK 71-13-11-400-010-A | Installation of the Left Fan Cowl |
| TASK 78-30-00-040-012-A | Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance |
| TASK 78-30-00-440-012-A | Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance |
| TASK 78-31-00-710-041-A | Operational Test of the Thrust Reverser System with the CFDS |
| TASK 78-31-00-710-041-A-02 | Operational test of the Thrust Reverser without the CFDS and Engine Running |
Hydraulic Control Unit (HCU) PipeSubtask 29-13-49-860-145-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(3) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(4) Depressurize the reservoir of the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-001).
Subtask 29-13-49-941-127-A ** ON A/C NOT FOR ALL (1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(3) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(4) Depressurize the reservoir of the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-001).
B. Safety Precautions
(1) Make sure that the engine 2 shutdown occurred not less than five minutes before you do this procedure.
(2) On the center pedestal, on ENG panel 115VU:
Subtask 29-13-49-865-111-A ** ON A/C NOT FOR ALL (1) Make sure that the engine 2 shutdown occurred not less than five minutes before you do this procedure.
(2) On the center pedestal, on ENG panel 115VU:
- Put a WARNING NOTICE(S) in position to tell persons not to operate the ENG/MODE selector switch and ENG/MASTER 2 control switch.
- Make sure that the ON legend of the ENG/FADEC GND PWR/2 pushbutton switch is off.
- Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 2.
C. Open, safety and tag this(these) circuit breaker(s):
Subtask 29-13-49-010-146-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/Y HYD/PUMP ENG2/CTL | 3701GD | Q36 |
| 123VU | Y HYD/ELEC/ELEC PUMP/NORM | 3801GX | AB03 |
D. Get Access
(1) Remove the access panel:
(a) FOR [1000EM2] 423AL (Ref. AMM TASK 54-52-11-000-002).
(2) Remove the fan cowl door:
(a) FOR [1000EM2] 447AL (Ref. AMM TASK 71-13-11-000-010)
(3) Put an ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position.
Subtask 29-13-49-040-086-A ** ON A/C NOT FOR ALL (1) Remove the access panel:
(a) FOR [1000EM2] 423AL (Ref. AMM TASK 54-52-11-000-002).
(2) Remove the fan cowl door:
(a) FOR [1000EM2] 447AL (Ref. AMM TASK 71-13-11-000-010)
(3) Put an ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position.
E. Deactivation of the Thrust Reverser
4. ProcedureWARNING:
MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.
(1) Make the thrust reverser unserviceable for maintenance (Ref. AMM TASK 78-30-00-040-012).Subtask 29-13-49-020-136-A ** ON A/C NOT FOR ALL
A. Get Access to the Yellow Hydraulic Control Unit (HCU) Pipe
(1) Put a CONTAINER 5 L (1.32 USGAL) in position below the case drain pipe.
(2) Remove the HCU return pipe (4) as follows:
(a) Loosen the union (1) and disconnect the HCU return pipe (4) from the case drain pipe.
(b) Loosen the union (3) and remove the HCU return pipe (4) from the HCU (11).
1 Use a second WRENCH - TORQUE, STANDARD to hold the union (13).
(c) Put the PLUG-BLANKING in each disconnected line end.
(3) Loosen the union (8) and disconnect the stow pipe (7) from the HCU (11).
(4) Loosen the union (10) and disconnect the deploy pipe (9) from the HCU (11).
(6) Remove the HCU pipe (6) as follows:
(a) Loosen the union (2) and disconnect the HCU pipe (6) from the pressure pipe.
(b) Loosen the union (5) and disconnect the HCU pipe (6) from the HCU (11).
1 Use a second WRENCH - TORQUE, STANDARD to hold the union (12).
(c) Put the PLUG-BLANKING in each disconnected line end.
(d) Remove and discard the HCU pipe (6).
Subtask 29-13-49-420-127-A ** ON A/C NOT FOR ALL (1) Put a CONTAINER 5 L (1.32 USGAL) in position below the case drain pipe.
(2) Remove the HCU return pipe (4) as follows:
(a) Loosen the union (1) and disconnect the HCU return pipe (4) from the case drain pipe.
(b) Loosen the union (3) and remove the HCU return pipe (4) from the HCU (11).
1 Use a second WRENCH - TORQUE, STANDARD to hold the union (13).
(c) Put the PLUG-BLANKING in each disconnected line end.
(3) Loosen the union (8) and disconnect the stow pipe (7) from the HCU (11).
(4) Loosen the union (10) and disconnect the deploy pipe (9) from the HCU (11).
CAUTION:
BEFORE YOU CONNECT THE PIPE TO THE HCU, MAKE SURE THAT YOU LOOSEN THE SCREWS OF THE HCU. IF YOU DO NOT OBEY THIS INSTRUCTION, THERE IS A RISK THAT YOU WILL USE TOO MUCH FORCE AND CAUSE DAMAGE TO THE PARTS.
(5) Loosen the screws (16).(6) Remove the HCU pipe (6) as follows:
(a) Loosen the union (2) and disconnect the HCU pipe (6) from the pressure pipe.
(b) Loosen the union (5) and disconnect the HCU pipe (6) from the HCU (11).
1 Use a second WRENCH - TORQUE, STANDARD to hold the union (12).
(c) Put the PLUG-BLANKING in each disconnected line end.
(d) Remove and discard the HCU pipe (6).
B. Installation of the Yellow HCU Pipe
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Remove the PLUG-BLANKING from each disconnected line end.
(4) Put the new AIPC 29-13-06-03-120 PIPE (6) in position.
(5) Connect the union (5) of the pipe (6) to the HCU (11).
(6) Connect the union (2) of the pipe (6) to the pressure pipe.
(7) Connect the union (8) of the stow pipe (7) to the HCU (11).
(8) Connect the union (10) of the deploy pipe (9) to the HCU (11).
(9) Install the return pipe (4) as follows:
(a) Put the return pipe (4) in position.
(b) Connect the union (3) to the HCU (11).
(c) Connect the union (1) to the case drain pipe.
(10) TORQUE the screws (16) to between 0.79 and 0.56 m.daN (69.91 and 49.56 lbf.in )
.
(11) TORQUE the union (1) to between 8.30 and 7.50 m.daN (61.21 and 55.31 lbf.ft ).
(12) Hold the union (13) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (3) to between 8.30 and 7.50 m.daN (61.21 and 55.31 lbf.ft ).
(13) Hold the union (12) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (5) to between 5.90 and 5.40 m.daN (43.51 and 39.82 lbf.ft ).
(14) Use the double torque procedure as follows:
(a) Torque the union (5) to the specified value.
(b) Loosen the union by one turn.
(c) Torque the union (5) to the specified value again.
(15) TORQUE the union (2) to between 5.90 and 5.40 m.daN (43.51 and 39.82 lbf.ft ).
(16) Use the double torque procedure as follows:.
(a) Torque the union (2) to the specified value.
(b) Loosen the union by one turn.
(c) Torque the union (2) to the specified value again.
(17) Hold the union (14) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (8) to between 5.90 and 5.40 m.daN (43.51 and 39.82 lbf.ft ).
(18) Hold the union (15) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (10) to between 8.30 and 7.50 m.daN (61.21 and 55.31 lbf.ft ).
(19) Remove the container.
(20) Identify the tightened union with a red line (Ref. AMM TASK 20-23-22-910-001).
Subtask 29-13-49-440-070-A ** ON A/C NOT FOR ALL (1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Remove the PLUG-BLANKING from each disconnected line end.
(4) Put the new AIPC 29-13-06-03-120 PIPE (6) in position.
(5) Connect the union (5) of the pipe (6) to the HCU (11).
(6) Connect the union (2) of the pipe (6) to the pressure pipe.
(7) Connect the union (8) of the stow pipe (7) to the HCU (11).
(8) Connect the union (10) of the deploy pipe (9) to the HCU (11).
(9) Install the return pipe (4) as follows:
(a) Put the return pipe (4) in position.
(b) Connect the union (3) to the HCU (11).
(c) Connect the union (1) to the case drain pipe.
(10) TORQUE the screws (16) to between 0.79 and 0.56 m.daN (69.91 and 49.56 lbf.in )
.(11) TORQUE the union (1) to between 8.30 and 7.50 m.daN (61.21 and 55.31 lbf.ft )
.(12) Hold the union (13) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (3) to between 8.30 and 7.50 m.daN (61.21 and 55.31 lbf.ft )
.(13) Hold the union (12) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (5) to between 5.90 and 5.40 m.daN (43.51 and 39.82 lbf.ft )
.(14) Use the double torque procedure as follows:
(a) Torque the union (5) to the specified value.
(b) Loosen the union by one turn.
(c) Torque the union (5) to the specified value again.
(15) TORQUE the union (2) to between 5.90 and 5.40 m.daN (43.51 and 39.82 lbf.ft )
.(16) Use the double torque procedure as follows:.
(a) Torque the union (2) to the specified value.
(b) Loosen the union by one turn.
(c) Torque the union (2) to the specified value again.
(17) Hold the union (14) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (8) to between 5.90 and 5.40 m.daN (43.51 and 39.82 lbf.ft )
.(18) Hold the union (15) with a second WRENCH - TORQUE, STANDARD and TORQUE the union (10) to between 8.30 and 7.50 m.daN (61.21 and 55.31 lbf.ft )
.(19) Remove the container.
(20) Identify the tightened union with a red line (Ref. AMM TASK 20-23-22-910-001).
C. Activation of the Thrust Reverser
(1) Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-440-012).
Subtask 29-13-49-865-112-A ** ON A/C NOT FOR ALL (1) Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-440-012).
D. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 29-13-49-614-056-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/Y HYD/PUMP ENG2/CTL | 3701GD | Q36 |
| 123VU | Y HYD/ELEC/ELEC PUMP/NORM | 3801GX | AB03 |
E. Pressurization of the Hydraulic Reservoir
(1) Pressurize the Yellow hydraulic reservoir of the engine 2 (Ref. AMM TASK 29-14-00-614-002).
Subtask 29-13-49-710-089-A ** ON A/C NOT FOR ALL (1) Pressurize the Yellow hydraulic reservoir of the engine 2 (Ref. AMM TASK 29-14-00-614-002).
F. Operational Tests
(1) Do the operational test of the Yellow hydraulic system (Ref. AMM TASK 29-13-00-710-002).
(2) Do the operational test of the thrust reverser system (Ref. AMM TASK 78-31-00-710-041).
(3) Make sure that there are no leaks at the tube connections.
5. Close-up(1) Do the operational test of the Yellow hydraulic system (Ref. AMM TASK 29-13-00-710-002).
(2) Do the operational test of the thrust reverser system (Ref. AMM TASK 78-31-00-710-041).
(3) Make sure that there are no leaks at the tube connections.
Subtask 29-13-49-410-124-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 the fan cowl doors (Ref. AMM TASK 71-13-11-400-010):
(a) FOR [1000EM2] 447AL.
(3) Install the access panel (Ref. AMM TASK 54-52-11-400-002):
(a) FOR [1000EM2] 423AL.
(4) Remove the access platform(s).
(5) Remove the WARNING NOTICE(S).
Subtask 29-13-49-862-064-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the fan cowl doors (Ref. AMM TASK 71-13-11-400-010):
(a) FOR [1000EM2] 447AL.
(3) Install the access panel (Ref. AMM TASK 54-52-11-400-002):
(a) FOR [1000EM2] 423AL.
(4) Remove the access platform(s).
(5) Remove the WARNING NOTICE(S).