DOC AIRBUS | AMM A320FInstallation of the Hydraulic Control Unit [CFMB]
TASK 78-31-51-400-042-A
Installation of the Hydraulic Control Unit
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Expendable Parts
E. Referenced Information
3. Job Set-up
Subtask 78-31-51-860-050-A ** ON A/C NOT FOR ALL
Subtask 78-31-51-420-051-B ** ON A/C NOT FOR ALL
Subtask 78-31-51-410-053-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 13:11:52 UTC
Installation of the Hydraulic Control Unit
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP1039) | acetone |
| (Material No.CP1041) | isopropyl alcohol |
| (Material No.CP2011) | stoddard solvent |
| (Material No.CP2212) | hydraulic fluid NSA-307-110 type 4 |
| (Material No.CP2245) | finish paint EA4 blue 5991 |
| (Material No.CP2318) | blindexite RT 342-2 |
| (Material No.CP2559) | ardrox 552 |
| (Material No.CP2560) | turco ind 79 |
| (Material No.CP2566) | mag-chem teksol |
| (Material No.CP2584) | degreasol 99 R |
| (Material No.CP2656) | mag-chem skysol |
| (Material No.CP8001) | lockwire 0.032 in. (0.8 mm) dia. |
| (Material No.CP8002) | lockwire 0.032 in. (0.8 mm) dia |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [1000EM1] (ENGINE-1) | |
| 437AL, 438AR, 452AR | |
| FOR [1000EM2] (ENGINE-2) | |
| 447AL, 448AR, 462AR | |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 145 | PREFORMED PACKINGS | AIPC 78-31-51-01-030 |
| 125 | PREFORMED PACKING | AIPC 78-31-51-01-050 |
| 170 | PREFORMED PACKING | AIPC 78-31-51-01-050 |
| 150 | PREFORMED PACKING | AIPC 78-31-51-01-080 |
| 155 | PREFORMED PACKING | AIPC 78-31-51-01-100 |
| REFERENCE | DESIGNATION |
|---|---|
| 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 71-13-00-010-040-B | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-040-B | Closing of the Fan Cowl Doors |
| TASK 78-30-00-081-041-B | Make the Thrust Reverser Serviceable after Maintenance |
| TASK 78-30-00-481-041-B | Make the Thrust Reverser Unserviceable for Maintenance |
| TASK 78-30-00-710-040-B | Thrust Reverser Hydraulic System Bleed Procedure |
| TASK 78-31-00-710-042-A | Operational Test of the Thrust Reverser System |
| TASK 78-36-00-010-040-B | Opening of the Thrust Reverser Doors |
| TASK 78-36-00-410-040-B | Closing of the Thrust Reverser Doors |
Hydraulic Control UnitSubtask 78-31-51-860-050-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
(1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
(3) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.
Subtask 78-31-51-010-058-A ** ON A/C NOT FOR ALL (1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
(3) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.
B. Get Access
(1) Make sure that the fan cowl doors are open (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Make sure that the right thrust reverser cowl door is open (Ref. AMM TASK 78-36-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
452AR
(b) FOR [1000EM2] (ENGINE-2)
462AR
Subtask 78-31-51-040-054-A ** ON A/C NOT FOR ALL 4. Procedure(1) Make sure that the fan cowl doors are open (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Make sure that the right thrust reverser cowl door is open (Ref. AMM TASK 78-36-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
452AR
(b) FOR [1000EM2] (ENGINE-2)
462AR
Subtask 78-31-51-420-051-B ** ON A/C NOT FOR ALL
A. Installation of the Hydraulic Control Unit (HCU)
(2) Remove the protective plugs from the HCU ports and the hydraulic lines.
(3) Make sure there is no unwanted matter inside the HCU ports and orifices.
(4) Lubricate the new preformed packings with hydraulic fluid NSA-307-110 type 4 (Material No.CP2212) .
(5) Apply hydraulic fluid NSA-307-110 type 4 (Material No.CP2212) to the threads of the unions.
(6) Put the AIPC 78-31-51-01-050 PREFORMED PACKING (125) on the union (130) and the AIPC 78-31-51-01-050 PREFORMED PACKING (170) on the union (165).
(7) Install the union (130) in the head supply port on the left side of the HCU.
(8) Install the union (165) in the pressure port on the right side of the HCU.
(9) TORQUE both unions to between 700 and 610 lbf.in (7.91 and 6.89 m.daN )
.
(10) Install the AIPC 78-31-51-01-080 PREFORMED PACKING (150) on the union (135).
(11) Install the union (135) in the return port on the left side of the HCU.
(12) TORQUE the union (135) to between 1017 and 929 lbf.in (11.49 and 10.50 m.daN ).
(13) Install the AIPC 78-31-51-01-030 PREFORMED PACKINGS (145) on the unions (140).
(14) Install the union (140) in the lock-in port on the left side of the HCU.
(15) Install the other union (140) in the lock-out port on the right side of the HCU.
(16) TORQUE both unions to between 300 and 260 lbf.in (3.39 and 2.94 m.daN ).
(17) Install the AIPC 78-31-51-01-100 PREFORMED PACKING (155) on the union (160).
(18) Install the union (160) in the rod supply port on the right side of the HCU.
(19) TORQUE the union (160) to between 410 and 370 lbf.in (4.63 and 4.18 m.daN ).
(20) Install the thermal blankets on the HCU if required, as follows:
(a) Put the thermal blankets (175) and (180) on the HCU (20).
(b) Make sure that the thermal blankets have the same shape as the HCU. There should be a clearance of 0.10 inch (2.54 mm) between the blankets and the adjacent parts.
(21) Attach the interface bracket (15) to the HCU with the bolts (120).
(22) TORQUE the bolts (120) to between 70 and 61 lbf.in (0.79 and 0.69 m.daN ).
(23) Apply a layer of blindexite RT 342-2 (Material No.CP2318) to the HCU mating surface.
(24) Install the two lower bolts (115) on the HCU mounting flange.
(25) Position the HCU (20) against the forward frame and install the other two bolts (115).
(26) TORQUE the bolts (115) to between 160 and 140 lbf.in (1.81 and 1.58 m.daN ).
Subtask 78-31-51-420-052-A ** ON A/C NOT FOR ALL NOTE: You should apply a witness line of finish paint EA4 blue 5991 (Material No.CP2245) on all nuts and connections when you have checked their torques.
(1) Remove the CAP-BLANKING from each electrical connector and receptacle.(2) Remove the protective plugs from the HCU ports and the hydraulic lines.
(3) Make sure there is no unwanted matter inside the HCU ports and orifices.
(4) Lubricate the new preformed packings with hydraulic fluid NSA-307-110 type 4 (Material No.CP2212) .
(5) Apply hydraulic fluid NSA-307-110 type 4 (Material No.CP2212) to the threads of the unions.
(6) Put the AIPC 78-31-51-01-050 PREFORMED PACKING (125) on the union (130) and the AIPC 78-31-51-01-050 PREFORMED PACKING (170) on the union (165).
(7) Install the union (130) in the head supply port on the left side of the HCU.
(8) Install the union (165) in the pressure port on the right side of the HCU.
(9) TORQUE both unions to between 700 and 610 lbf.in (7.91 and 6.89 m.daN )
. (10) Install the AIPC 78-31-51-01-080 PREFORMED PACKING (150) on the union (135).
(11) Install the union (135) in the return port on the left side of the HCU.
(12) TORQUE the union (135) to between 1017 and 929 lbf.in (11.49 and 10.50 m.daN )
. (13) Install the AIPC 78-31-51-01-030 PREFORMED PACKINGS (145) on the unions (140).
(14) Install the union (140) in the lock-in port on the left side of the HCU.
(15) Install the other union (140) in the lock-out port on the right side of the HCU.
(16) TORQUE both unions to between 300 and 260 lbf.in (3.39 and 2.94 m.daN )
. (17) Install the AIPC 78-31-51-01-100 PREFORMED PACKING (155) on the union (160).
(18) Install the union (160) in the rod supply port on the right side of the HCU.
(19) TORQUE the union (160) to between 410 and 370 lbf.in (4.63 and 4.18 m.daN )
. (20) Install the thermal blankets on the HCU if required, as follows:
(a) Put the thermal blankets (175) and (180) on the HCU (20).
(b) Make sure that the thermal blankets have the same shape as the HCU. There should be a clearance of 0.10 inch (2.54 mm) between the blankets and the adjacent parts.
(21) Attach the interface bracket (15) to the HCU with the bolts (120).
(22) TORQUE the bolts (120) to between 70 and 61 lbf.in (0.79 and 0.69 m.daN )
. (23) Apply a layer of blindexite RT 342-2 (Material No.CP2318) to the HCU mating surface.
(24) Install the two lower bolts (115) on the HCU mounting flange.
(25) Position the HCU (20) against the forward frame and install the other two bolts (115).
(26) TORQUE the bolts (115) to between 160 and 140 lbf.in (1.81 and 1.58 m.daN )
. B. Connect the Pipes to the Right Side of the HCU as Follows
(1) Connect the head supply pipe (70) to the HCU (20).
(2) TORQUE the coupling nut to between 500 and 450 lbf.in (5.65 and 5.09 m.daN ).
(3) Position the support (90) against the interface bracket (15).
(4) Attach the head supply pipe (70) and the support (90) to the interface bracket (15) with the nut (80).
(5) TORQUE the nut (80) to between 700 and 610 lbf.in (7.91 and 6.89 m.daN ).
(6) Attach the latch return pipe (35) and the support (90) to the interface bracket (15) with the nut (85).
(7) TORQUE the nut (85) to between 300 and 260 lbf.in (3.39 and 2.94 m.daN ).
(9) TORQUE the coupling nut to between 260 and 235 lbf.in (2.94 and 2.66 m.daN ).
(10) Attach the rod supply pipe (75) to the interface bracket (15) with the nut (105).
(11) TORQUE the nut (105) to between 420 and 376 lbf.in (4.75 and 4.25 m.daN ).
(12) Connect the latch supply pipe (110) to the HCU (20).
(13) TORQUE the coupling nut to between 150 and 130 lbf.in (1.70 and 1.47 m.daN ).
Subtask 78-31-51-420-053-A ** ON A/C NOT FOR ALL (1) Connect the head supply pipe (70) to the HCU (20).
(2) TORQUE the coupling nut to between 500 and 450 lbf.in (5.65 and 5.09 m.daN )
. (3) Position the support (90) against the interface bracket (15).
(4) Attach the head supply pipe (70) and the support (90) to the interface bracket (15) with the nut (80).
(5) TORQUE the nut (80) to between 700 and 610 lbf.in (7.91 and 6.89 m.daN )
. (6) Attach the latch return pipe (35) and the support (90) to the interface bracket (15) with the nut (85).
(7) TORQUE the nut (85) to between 300 and 260 lbf.in (3.39 and 2.94 m.daN )
. NOTE: A clearance of 0.15 in. to 0.23 in. (4 mm to 6 mm) is required between the HCU heatshield and the Return Pipe of the Right Latch (35).
(8) Connect the rod supply pipe (75) to the HCU (20). (9) TORQUE the coupling nut to between 260 and 235 lbf.in (2.94 and 2.66 m.daN )
. (10) Attach the rod supply pipe (75) to the interface bracket (15) with the nut (105).
(11) TORQUE the nut (105) to between 420 and 376 lbf.in (4.75 and 4.25 m.daN )
. (12) Connect the latch supply pipe (110) to the HCU (20).
(13) TORQUE the coupling nut to between 150 and 130 lbf.in (1.70 and 1.47 m.daN )
. C. Connect the Pipes and Hoses to the Left Side of the HCU as Follows
(1) Install one end of the CVR pipe (100) in the support (90) and attach it with the nut (95).
(2) TORQUE the nut (95) to between 150 and 130 lbf.in (1.70 and 1.47 m.daN ).
(3) Connect the other end CVR pipe (100) to the check valve restrictor on the HCU.
(4) TORQUE the coupling nut on the CRV tube (100) to between 260 and 235 lbf.in (2.94 and 2.66 m.daN ).
(5) Connect the supply hose (50) to the HCU (20).
(6) TORQUE the coupling nut on the hose (50) to between 520 and 470 lbf.in (5.88 and 5.31 m.daN ).
(7) Connect the return hose (45) to the HCU (20).
(8) TORQUE the coupling nut on the hose (45) to between 732 and 660 lbf.in (8.27 and 7.46 m.daN ).
(9) Connect the latch return hose (40) to the HCU (20).
(10) TORQUE the coupling nut on the hose (40) to between 125 and 113 lbf.in (1.41 and 1.28 m.daN ).
(11) Connect the latch supply hose (55) to the latch return pipe (35) on the interface bracket (15).
(12) TORQUE the coupling nut on the hose (55) to between 125 and 113 lbf.in (1.41 and 1.28 m.daN ).
(13) Connect the head supply hose (60) to the head supply pipe (70) on the interface bracket (15).
(14) TORQUE the coupling nut on the hose (60) to between 600 and 540 lbf.in (6.78 and 6.10 m.daN ).
(15) Connect the rod supply hose (65) to the rod supply pipe (75) on the interface bracket (15).
(16) TORQUE the coupling nut on the hose (65) to between 300 and 270 lbf.in (3.39 and 3.05 m.daN ).
(17) Put the clamps (10, 12) on the thrust reverser harness (30). Attach the clamp (10) to the interface bracket (15) with the bolt (5) and the nut (25).
(18) TORQUE the nut (25) to between 40 and 30 lbf.in (0.45 and 0.34 m.daN ).
(19) Connect the electrical connector 4101KS-A to solenoid A of the HCU.
(21) Connect the electrical connector 4102KS-A to the HCU pressure switch.
Subtask 78-31-51-420-054-A ** ON A/C NOT FOR ALL (1) Install one end of the CVR pipe (100) in the support (90) and attach it with the nut (95).
(2) TORQUE the nut (95) to between 150 and 130 lbf.in (1.70 and 1.47 m.daN )
. (3) Connect the other end CVR pipe (100) to the check valve restrictor on the HCU.
(4) TORQUE the coupling nut on the CRV tube (100) to between 260 and 235 lbf.in (2.94 and 2.66 m.daN )
. (5) Connect the supply hose (50) to the HCU (20).
(6) TORQUE the coupling nut on the hose (50) to between 520 and 470 lbf.in (5.88 and 5.31 m.daN )
. (7) Connect the return hose (45) to the HCU (20).
(8) TORQUE the coupling nut on the hose (45) to between 732 and 660 lbf.in (8.27 and 7.46 m.daN )
. (9) Connect the latch return hose (40) to the HCU (20).
(10) TORQUE the coupling nut on the hose (40) to between 125 and 113 lbf.in (1.41 and 1.28 m.daN )
. (11) Connect the latch supply hose (55) to the latch return pipe (35) on the interface bracket (15).
(12) TORQUE the coupling nut on the hose (55) to between 125 and 113 lbf.in (1.41 and 1.28 m.daN )
. (13) Connect the head supply hose (60) to the head supply pipe (70) on the interface bracket (15).
(14) TORQUE the coupling nut on the hose (60) to between 600 and 540 lbf.in (6.78 and 6.10 m.daN )
. (15) Connect the rod supply hose (65) to the rod supply pipe (75) on the interface bracket (15).
(16) TORQUE the coupling nut on the hose (65) to between 300 and 270 lbf.in (3.39 and 3.05 m.daN )
. (17) Put the clamps (10, 12) on the thrust reverser harness (30). Attach the clamp (10) to the interface bracket (15) with the bolt (5) and the nut (25).
(18) TORQUE the nut (25) to between 40 and 30 lbf.in (0.45 and 0.34 m.daN )
. (19) Connect the electrical connector 4101KS-A to solenoid A of the HCU.
NOTE: If necessary, use the PLIERS - NOSE, SOFT, LONG to tighten the electrical connectors.
(20) Connect the electrical connector 4101KS-B to solenoid B of the HCU. (21) Connect the electrical connector 4102KS-A to the HCU pressure switch.
D. Remove the Drain Can from Under the HCU
(1) Remove the protective cover and examine the engine to make sure there is no hydraulic fluid on the compressor cases.
Subtask 78-31-51-110-050-A ** ON A/C NOT FOR ALL (1) Remove the protective cover and examine the engine to make sure there is no hydraulic fluid on the compressor cases.
E. If Hydraulic Fluid is Found, Clean the Compressor Case as Follows
(1) Remove hydraulic fluid from the compressor cases with a clean, dry cloth.
(2) Cleaning:
(b) Dry the area with a clean, dry cloth.
Subtask 78-31-51-210-050-A ** ON A/C NOT FOR ALL (1) Remove hydraulic fluid from the compressor cases with a clean, dry cloth.
(2) Cleaning:
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
(a) Clean all remaining hydraulic fluid from the compressor case with a clean cloth moistened with isopropyl alcohol (Material No.CP1041) or acetone (Material No.CP1039) or stoddard solvent (Material No.CP2011) or ardrox 552 (Material No.CP2559) or turco ind 79 (Material No.CP2560) or mag-chem teksol (Material No.CP2566) or degreasol 99 R (Material No.CP2584) or mag-chem skysol (Material No.CP2656) . (b) Dry the area with a clean, dry cloth.
F. Check the Red Clogging Indicator
(1) Make sure that the red clogging indicator is not extended.
(2) If the clogging indicator is extended, set it to the operational position as follows:
(a) Cut the lockwire and remove the retaining ring and the glass bowl from the HCU.
(b) Push the red indicator in to set the normal (operational) position.
(c) Install the bowl and the retainer over the indicator. Tighten the retainer with your hand.
(d) Safety the retainer withCP8001 lockwire 0.032 in. (0.8 mm) dia. CP8002 lockwire 0.032 in. (0.8 mm) dia
5. Close-up(1) Make sure that the red clogging indicator is not extended.
(2) If the clogging indicator is extended, set it to the operational position as follows:
(a) Cut the lockwire and remove the retaining ring and the glass bowl from the HCU.
(b) Push the red indicator in to set the normal (operational) position.
(c) Install the bowl and the retainer over the indicator. Tighten the retainer with your hand.
(d) Safety the retainer with
Subtask 78-31-51-410-053-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) Close the right thrust reverser cowl door (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
452AR
(b) FOR [1000EM2] (ENGINE-2)
462AR
(3) Remove the access platform(s).
Subtask 78-31-51-440-051-A ** ON A/C NOT FOR ALL Subtask 78-31-51-614-051-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the right thrust reverser cowl door (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
452AR
(b) FOR [1000EM2] (ENGINE-2)
462AR
(3) Remove the access platform(s).
C. Pressurization of the Hydraulic Reservoir
(1) For engine 1 pressurize the Green hydraulic reservoir (Ref. AMM TASK 29-14-00-614-002).
(2) For engine 2 pressurize the Yellow hydraulic reservoir (Ref. AMM TASK 29-14-00-614-002).
Subtask 78-31-51-710-052-A ** ON A/C NOT FOR ALL Subtask 78-31-51-410-054-A ** ON A/C NOT FOR ALL (1) For engine 1 pressurize the Green hydraulic reservoir (Ref. AMM TASK 29-14-00-614-002).
(2) For engine 2 pressurize the Yellow hydraulic reservoir (Ref. AMM TASK 29-14-00-614-002).
E. Close fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR
Subtask 78-31-51-710-051-A ** ON A/C NOT FOR ALL (1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR