DOC AIRBUS | AMM A320FDeactivation of the Alternate Braking with disconnection of the Yellow Hydraulic Supply
TASK 32-43-00-040-001-A
Deactivation of the Alternate Braking with disconnection of the Yellow Hydraulic Supply
MMEL 32-44-01A
YELLOW SYSTEM BRAKE
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Job Set-up
Subtask 32-43-00-941-050-A
Subtask 32-43-00-040-050-A
Subtask 32-43-00-860-058-A
[Rev.10 from 2021]
2026.04.01 00:48:38 UTC
Deactivation of the Alternate Braking with disconnection of the Yellow Hydraulic Supply
WARNING:
MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.
WARNING:
MAKE SURE THAT THE CONTROLS AGREE WITH THE POSITION OF THE ITEMS THEY OPERATE BEFORE YOU PRESSURIZE A HYDRAULIC SYSTEM. UNWANTED MOVEMENT OF HYDRAULICALLY OPERATED ITEMS CAN CAUSE SERIOUS INJURY AND/OR DAMAGE.
Task Summary
1. Reason for the Job| Access | Test | Specific Tools | Mhr | E/T | Nb Men |
|---|---|---|---|---|---|
| NO | YES | NO | 0.3 | 0.3 | 1 |
MMEL 32-44-01A
YELLOW SYSTEM BRAKE
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | CONTAINER 5 L (1.32 USGAL) |
| No specific | AR | HOSE - VINYL |
| No specific | AR | PLACARD |
| No specific | AR | TAPE - ADHESIVE |
| No specific | AR | TAPE - WIDE SELF-ADHESIVE - FABRIC |
| No specific | AR | WARNING NOTICE(S) |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.02ABA1) | Phosphate Ester Hydraulic Fluid-General Power - - |
| (Material No.14QFB1) | Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 12-12-29-611-001-A | Fill the Hydraulic Fluid Reservoir with a Hand Pump |
| TASK 24-41-00-861-002-A | Energize the Aircraft Electrical Circuits from the External Power |
| TASK 24-41-00-861-002-A-01 | Energize the Aircraft Electrical Circuits from the APU |
| TASK 24-41-00-861-002-A-02 | Energize the Aircraft Electrical Circuits from Engine 1(2) |
| TASK 24-41-00-862-002-A | De-energize the Aircraft Electrical Circuits Supplied from the External Power |
| TASK 24-41-00-862-002-A-01 | De-energize the Aircraft Electrical Circuits Supplied from the APU |
| TASK 24-41-00-862-002-A-02 | De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2) |
| TASK 29-10-00-863-002-A | Pressurize the Yellow Hydraulic System with a Hydraulic Ground Power-Cart |
| TASK 29-10-00-864-001-A | Depressurize the Green Hydraulic System |
| TASK 29-10-00-864-002-A | Depressurize the Yellow Hydraulic System |
| TASK 29-14-00-614-001-A | Depressurization of the Hydraulic Reservoirs |
| TASK 29-24-00-863-001-A | Pressurize the Yellow Hydraulic System with the Electric Pump |
| TASK 32-11-12-000-001-A | Removal of the MLG Hydraulic Dressings |
| TASK 32-43-00-710-001-A | Operational Check of Alternate Braking System |
Alternate Brake DeactivationSubtask 32-43-00-941-050-A
A. Safety Precautions
(1) Put the WARNING NOTICE(S) in position to tell persons not to operate the landing gear control lever and the brake pedals.
Subtask 32-43-00-860-057-A (1) Put the WARNING NOTICE(S) in position to tell persons not to operate the landing gear control lever and the brake pedals.
B. Aircraft Maintenance Configuration
(1) Depressurize the yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(2) Parking brake configuration
(3) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002)
Subtask 32-43-00-865-050-A (1) Depressurize the yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(2) Parking brake configuration
CAUTION:
MAKE SURE THAT ALL THE PISTONS OF THE BRAKE ARE IN THE RELEASED POSITION.
(a) Make sure that the parking brake control-switch is set to OFF before you do this procedure. (3) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002)
C. Make sure that this(these) circuit breaker(s) is(are) closed:
4. Procedure| PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | L/G/Y BRK/PRESS/IND | 61GG | C10 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | ABCU &/Y BRK/PRESS IND | 61GG | C10 |
| ** ON A/C ALL | |||
| 121VU | HYDRAULIC/BRAKING AND STEERING/SYS2/SPLY | 4GG | M36 |
| 121VU | HYDRAULIC/BRAKING AND STEERING/SYS2/CTL | 3GG | M35 |
| 121VU | HYDRAULIC/BRAKING AND STEERING/SYS1/CTL | 1GG | M34 |
| 121VU | HYDRAULIC/BRAKING AND STEERING/SYS1/IND AND/SPLY | 2GG | M33 |
Subtask 32-43-00-040-050-A
A. Deactivation with Isolation of Yellow Hydraulic Supply
(1) Loosen the knurled sleeve (1) of the Yellow half-coupling (2). Turn and disconnect the coupling.
(2) Clean the knurled sleeve (1). Apply 2 or 3 turns of the TAPE - ADHESIVE (20 to 30 mm wide) to the sleeve (1).
(3) Tightly wind 3 or 4 turns of the lockwire around the middle of the sleeve (1) with the tape.
(4) Twist the14QFB1 Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -
(5) Remove the bleed screw plug (4) from the bleed screw (3).
(6) Connect a HOSE - VINYL to the bleed screw related to of the Yellow system and put the other end in a CONTAINER 5 L (1.32 USGAL) that contains Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(7) Slowly loosen the bleed screw (3) to release hydraulic residual pressure from the brake.
(8) Tighten the bleed screw (3).
(9) Disconnect the vinyl hose.
(10) Install the bleed screw plug (4) on the bleed screw (3).
Subtask 32-43-00-040-051-A (1) Loosen the knurled sleeve (1) of the Yellow half-coupling (2). Turn and disconnect the coupling.
(2) Clean the knurled sleeve (1). Apply 2 or 3 turns of the TAPE - ADHESIVE (20 to 30 mm wide) to the sleeve (1).
(3) Tightly wind 3 or 4 turns of the lockwire around the middle of the sleeve (1) with the tape.
(4) Twist the
(5) Remove the bleed screw plug (4) from the bleed screw (3).
(6) Connect a HOSE - VINYL to the bleed screw related to of the Yellow system and put the other end in a CONTAINER 5 L (1.32 USGAL) that contains Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(7) Slowly loosen the bleed screw (3) to release hydraulic residual pressure from the brake.
(8) Tighten the bleed screw (3).
(9) Disconnect the vinyl hose.
(10) Install the bleed screw plug (4) on the bleed screw (3).
B. Deactivation of the Wheel Brake with Disconnection of Flexible Hoses from the Alternate Braking System if there is a Leak
(1) Depressurize the Yellow hydraulic reservoir (Ref. AMM TASK 29-14-00-614-001).
(2) For one wheel brake only, remove the flexible hoses located between the rigid MLG hydraulic pipes and the wheel brake, on the alternate braking systems.
(3) Remove the flexible hose (1) from the brake hydraulic self-sealing-coupling and from the flexible hose (5) connection (Ref. AMM TASK 32-11-12-000-001).
(4) Clean the brake hydraulic self-sealing-coupling and apply two or three turns of the TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.).
(5) Remove the flexible hose (5) from the flexible hose (1) connection and from the union (6) (Ref. AMM TASK 32-11-12-000-001).
(6) Install blanking cap on the related union (6) to make sure that there is no leak.
(7) Remove the bleed screw plug (4) from the related bleed screw (3).
(8) Connect a HOSE - VINYL to a bleed screw (3) and put the other end in a CONTAINER 5 L (1.32 USGAL) that contains Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(9) Slowly loosen the bleed screw (3) to release the remaining hydraulic pressure from the wheel brake.
(10) Tighten the bleed screw (3).
(11) Disconnect the HOSE - VINYL.
(12) Install the bleed screw plug (4) on the bleed screw (3).
(13) Do the operational check of the alternate braking system (Ref. AMM TASK 32-43-00-710-001). Make sure that there is no leak.
(14) Make sure that there is no sign of overstrain damage on the band clamps that connect the hydraulic pipe to the MLG.
(15) Make sure that there are no signs of damage on the mounting locations between the two ends of the hydraulic pipes and the MLG.
(16) Do a leak check at the blanking caps after each flight during the permitted repair intervals.
(17) Do a detailed visual inspection of the adjacent brake hose and harness to make sure that there are no signs of chafing, damage or leak. Do this inspection after each flight during the permitted repair intervals.
Subtask 32-43-00-910-050-A (1) Depressurize the Yellow hydraulic reservoir (Ref. AMM TASK 29-14-00-614-001).
(2) For one wheel brake only, remove the flexible hoses located between the rigid MLG hydraulic pipes and the wheel brake, on the alternate braking systems.
(3) Remove the flexible hose (1) from the brake hydraulic self-sealing-coupling and from the flexible hose (5) connection (Ref. AMM TASK 32-11-12-000-001).
(4) Clean the brake hydraulic self-sealing-coupling and apply two or three turns of the TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.).
(5) Remove the flexible hose (5) from the flexible hose (1) connection and from the union (6) (Ref. AMM TASK 32-11-12-000-001).
(6) Install blanking cap on the related union (6) to make sure that there is no leak.
(7) Remove the bleed screw plug (4) from the related bleed screw (3).
(8) Connect a HOSE - VINYL to a bleed screw (3) and put the other end in a CONTAINER 5 L (1.32 USGAL) that contains Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(9) Slowly loosen the bleed screw (3) to release the remaining hydraulic pressure from the wheel brake.
(10) Tighten the bleed screw (3).
(11) Disconnect the HOSE - VINYL.
(12) Install the bleed screw plug (4) on the bleed screw (3).
(13) Do the operational check of the alternate braking system (Ref. AMM TASK 32-43-00-710-001). Make sure that there is no leak.
(14) Make sure that there is no sign of overstrain damage on the band clamps that connect the hydraulic pipe to the MLG.
(15) Make sure that there are no signs of damage on the mounting locations between the two ends of the hydraulic pipes and the MLG.
(16) Do a leak check at the blanking caps after each flight during the permitted repair intervals.
(17) Do a detailed visual inspection of the adjacent brake hose and harness to make sure that there are no signs of chafing, damage or leak. Do this inspection after each flight during the permitted repair intervals.
C. Precaution
Subtask 32-43-00-860-056-A D. Aircraft Maintenance Configuration
(1) Pressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-002) or (Ref. AMM TASK 29-24-00-863-001).
Subtask 32-43-00-710-050-A (1) Pressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-002) or (Ref. AMM TASK 29-24-00-863-001).
E. Test
(1) Do this test.
5. Close-up(1) Do this test.
NOTE: During this test, make sure that:
the Green hydraulic system is depressurized (Ref. AMM TASK 29-10-00-864-001),
or, on the panel 402VU, the A/SKID & NOSE WHEEL switch is set to OFF.
the Green hydraulic system is depressurized (Ref. AMM TASK 29-10-00-864-001),
or, on the panel 402VU, the A/SKID & NOSE WHEEL switch is set to OFF.
| ACTION | RESULT |
|---|---|
| 1.Push in fully the related brake pedals and hold them pushed in. | Make sure that there are no leaks on the hydraulic pressure line you disconnected. |
| 2.Release the brake pedals. | |
Subtask 32-43-00-860-058-A
A. Put the aircraft back to its initial configuration.
(1) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(2) Make sure that the level of the hydraulic fluid is correct in the Yellow hydraulic reservoir. Add some hydraulic fluid if it is necessary (Ref. AMM TASK 12-12-29-611-001).
(3) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
(4) Remove the WARNING NOTICE(S).
(5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(6) Make an entry in the logbook to tell persons that the alternate braking is deactivated.
(7) In the cockpit, install a PLACARD to tell the crew that the ALTERNATE BRAKING on the WHEEL 1 (2, 3, 4) is not operational.
(1) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(2) Make sure that the level of the hydraulic fluid is correct in the Yellow hydraulic reservoir. Add some hydraulic fluid if it is necessary (Ref. AMM TASK 12-12-29-611-001).
(3) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
(4) Remove the WARNING NOTICE(S).
(5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(6) Make an entry in the logbook to tell persons that the alternate braking is deactivated.
(7) In the cockpit, install a PLACARD to tell the crew that the ALTERNATE BRAKING on the WHEEL 1 (2, 3, 4) is not operational.