DOC AIRBUS | AMM A320FThrust Reverser Hydraulic System Bleed Procedure [CFMB]
TASK 78-30-00-710-040-B
Thrust Reverser Hydraulic System Bleed Procedure
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 78-30-00-941-053-A ** ON A/C NOT FOR ALL
Subtask 78-30-00-710-052-B ** ON A/C NOT FOR ALL
Subtask 78-30-00-410-052-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 03:23:48 UTC
Thrust Reverser Hydraulic System Bleed Procedure
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 1M(3 FT) |
| No specific | 1 | CONTAINER 20 L - SHALLOW |
| No specific | AR | HOSE - TRANSPARENT, SKYDROL RESISTANT |
| No specific | AR | WARNING NOTICE(S) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [1000EM1] (ENGINE-1) | |
| 437AL, 438AR | |
| FOR [1000EM2] (ENGINE-2) | |
| 447AL, 448AR | |
| 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 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 29-23-00-864-001-A | Depressurize the Green and Yellow Hydraulic Systems after Operation of the PTU |
| 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 78-31-00-710-042-A | Operational Test of the Thrust Reverser System |
Hydraulic Control Unit Bleed ValveSubtask 78-30-00-941-053-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
Subtask 78-30-00-010-052-A ** ON A/C NOT FOR ALL (1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
B. Get Access
(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.
4. Procedure(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.
Subtask 78-30-00-710-052-B ** ON A/C NOT FOR ALL
A. Bleed the air from the thrust reverser hydraulic system as follows:
Make sure that the thrust reverser doors operate smoothly.
(2) If the thrust reverser doors operate smoothly, it is not necessary to do the steps that follow.
(3) If the doors shake during opening or closing, do this HCU bleeding procedure:
(a) Depressurize the hydraulic system (Ref. AMM TASK 29-23-00-864-001).
(b) Make sure that the hydraulic reservoirs are pressurized at 50 psi (3.45 bar) (Ref. AMM TASK 29-14-00-614-002).
(c) Bleeding of the air from the thrust reverser hydraulic system
(d) Remove the cap from the HCU bleed valve and attach one end of the HOSE - TRANSPARENT, SKYDROL RESISTANT to the valve.
(e) Put the other end of the transparent tube in the container.
(f) Slowly open the bleed valve and allow hydraulic fluid to drain.
(g) Continue bleeding as long as the quantity of air bubbles can be seen to be decreasing, and also until a steady flow is achieved. After a reasonable time, when the observable quantity of air bubbles is not changing, close the HCU bleed valve.
Make sure that the thrust reverser doors operate smoothly.
(i) If the doors shake during opening or closing, repeat the HCU bleeding procedure as follows :
(k) Remove the transparent tube and install the cap on the bleed valve.
(l) Remove the container from below the HCU bleed valve.
(m) Make sure that the level of the hydraulic fluid in the reservoir is correct. If necessary, fill the reservoir (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
5. Close-upWARNING:
DO NOT OPEN THE HCU BLEED VALVE WHEN THE HYDRAULIC CIRCUIT IS PRESSURIZED.
REMOVAL OF THE CAP WHEN THE HYDRAULIC CIRCUIT IS PRESSURIZED CAN RESULT IN INJURY TO PERSONS.
(1) Operate the thrust reverser for 10 deploy-to-stow cycles (Ref. AMM TASK 78-31-00-710-042). Make sure that the thrust reverser doors operate smoothly.
(2) If the thrust reverser doors operate smoothly, it is not necessary to do the steps that follow.
(3) If the doors shake during opening or closing, do this HCU bleeding procedure:
(a) Depressurize the hydraulic system (Ref. AMM TASK 29-23-00-864-001).
(b) Make sure that the hydraulic reservoirs are pressurized at 50 psi (3.45 bar) (Ref. AMM TASK 29-14-00-614-002).
(c) Bleeding of the air from the thrust reverser hydraulic system
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1 Put a CONTAINER 20 L - SHALLOW below the HCU bleed valve to catch the hydraulic fluid. (d) Remove the cap from the HCU bleed valve and attach one end of the HOSE - TRANSPARENT, SKYDROL RESISTANT to the valve.
(e) Put the other end of the transparent tube in the container.
(f) Slowly open the bleed valve and allow hydraulic fluid to drain.
(g) Continue bleeding as long as the quantity of air bubbles can be seen to be decreasing, and also until a steady flow is achieved. After a reasonable time, when the observable quantity of air bubbles is not changing, close the HCU bleed valve.
NOTE: Use a second wrench to hold the HCU bleed valve when you turn the nut to close the valve.
(h) Operate the thrust reverser for 10 deploy-to-stow cycles (Ref. AMM TASK 78-31-00-710-042). Make sure that the thrust reverser doors operate smoothly.
(i) If the doors shake during opening or closing, repeat the HCU bleeding procedure as follows :
NOTE: Do not repeat the HCU bleeding procedure more than tow times, refer to thrust reverser trouble shooting procedure.
- depressurize the hydraulic system (Ref. AMM TASK 29-23-00-864-001)
- repeat steps (f) through (h).
If reverser operates smoothly, proceed from step (j).
(k) Remove the transparent tube and install the cap on the bleed valve.
(l) Remove the container from below the HCU bleed valve.
(m) Make sure that the level of the hydraulic fluid in the reservoir is correct. If necessary, fill the reservoir (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
Subtask 78-30-00-410-052-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 fan cowl doors: (Ref. AMM TASK 71-13-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowl doors: (Ref. AMM TASK 71-13-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).