DOC AIRBUS | AMM A320FDeactivation of the Main Wheel Brakes
TASK 32-42-00-040-003-A
Deactivation of the Main Wheel Brakes
MMEL 32-42-01A
MAIN WHEEL BRAKE
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Job Set-up
Subtask 32-42-00-941-061-A
Subtask 32-42-00-040-060-A
Subtask 32-42-00-860-070-A
[Rev.10 from 2021]
2026.04.01 00:47:24 UTC
Deactivation of the Main Wheel Brakes
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.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
Task Summary
1. Reason for the Job| Access | Test | Specific Tools | Mhr | E/T | Nb Men |
|---|---|---|---|---|---|
| NO | YES | YES | 1.0 | 2.0 | 2 |
MMEL 32-42-01A
MAIN WHEEL BRAKE
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | CAP - BLANKING |
| No specific | AR | CONTAINER 5 L (1.32 USGAL) |
| No specific | AR | HOSE - VINYL |
| No specific | AR | PLACARD |
| 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 - |
| No specific | corrosion-resistant steel lockwire dia 0.8 mm |
| 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 29-10-00-864-001-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 29-14-00-614-002-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 29-23-00-863-001-A | Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump |
| 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 32-41-11-400-006-A | Installation of the MLG Wheel |
| TASK 32-42-00-710-001-A | Operational Check of the Normal Braking System |
| TASK 32-42-00-720-002-A | Functional Test of the Tachometers and the Anti-Skid System with the Normal Braking System ON |
| TASK 32-42-00-720-003-A | Functional Test of the tachometers with the AIDS. |
| TASK 32-42-27-000-001-A | Removal of the Brake |
| TASK 32-43-00-710-001-A | Operational Check of Alternate Braking System |
| TASK 32-46-00-740-001-A | BITE Test of the BSCU |
Deactivation without Brake RemovalSubtask 32-42-00-941-061-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 32-42-00-740-057-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. BITE Test
(1) Do the BITE test of the BSCU (Ref. AMM TASK 32-46-00-740-001).
(a) If there is a fault message, make sure that it is not related to the tachometer of the serviceable brake.
Subtask 32-42-00-860-068-A (1) Do the BITE test of the BSCU (Ref. AMM TASK 32-46-00-740-001).
(a) If there is a fault message, make sure that it is not related to the tachometer of the serviceable brake.
C. Aircraft Maintenance Configuration
(1) Depressurize the Green and Yellow hydraulic systems (Ref. AMM TASK 29-10-00-864-001) (Ref. AMM TASK 29-10-00-864-002).
(2) Parking brake configuration
4. Procedure(1) Depressurize the Green and Yellow hydraulic systems (Ref. AMM TASK 29-10-00-864-001) (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 BRK control switch is set to OFF before you do the deactivation. Subtask 32-42-00-040-060-A
A. Deactivations of the Main Wheel Brakes
Subtask 32-42-00-040-052-A NOTE: There are three procedures to deactivate a wheel brake:
- Deactivation without removal of the wheel brake.
- Deactivation with removal of the wheel brake system of the wheel brake.
- Deactivation of the wheel brake with disconnection of flexible hoses from normal and alternate braking system if there is a leak.
If the wheel brake cannot move and/or if the stators, rotors, torque tubes or heat shield are damaged, do the removal and the deactivation of the wheel brake. If you find no damage, do only the deactivation of the wheel brake.
B. Deactivation without Removal of the brake
(1) Loosen the two knurled sleeves (1) and (4) of the half couplings (2) and (3). Turn and disconnect the half couplings.
(2) Clean the sleeves (1) and (4) and apply two or three turns of the TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.7874 in.) to 30 mm (1.1811 in.).
(3) Tightly wind three or four turns of the14QFB1 Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -
(4) Twist the lockwire and put it through the nearest locking hole you can get access to in the hexagonal head of the fixed half couplings (2) and (3).
Tighten the lockwire and twist it.
(5) Remove the two bleed screw plugs (6) from the bleed screw.
(6) Connect a HOSE - VINYL to a bleed screw (5) 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 (5) to release hydraulic residual pressure from the brake.
(8) Tighten the bleed screw.
(9) Disconnect the vinyl hose.
(10) Install the bleed screw plug (6) on the bleed screw (5).
(11) Do the same operations for the other bleed screw.
Subtask 32-42-00-910-052-A (1) Loosen the two knurled sleeves (1) and (4) of the half couplings (2) and (3). Turn and disconnect the half couplings.
(2) Clean the sleeves (1) and (4) and apply two or three turns of the TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.7874 in.) to 30 mm (1.1811 in.).
(3) Tightly wind three or four turns of the
(4) Twist the lockwire and put it through the nearest locking hole you can get access to in the hexagonal head of the fixed half couplings (2) and (3).
Tighten the lockwire and twist it.
(5) Remove the two bleed screw plugs (6) from the bleed screw.
(6) Connect a HOSE - VINYL to a bleed screw (5) 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 (5) to release hydraulic residual pressure from the brake.
(8) Tighten the bleed screw.
(9) Disconnect the vinyl hose.
(10) Install the bleed screw plug (6) on the bleed screw (5).
(11) Do the same operations for the other bleed screw.
C. Precaution:
Subtask 32-42-00-040-053-A ** ON A/C NOT FOR ALL D. Deactivation with the Brake Removal
(1) Remove the brake (Ref. AMM TASK 32-42-27-000-001).
(6) Install the main landing-gear wheel (Ref. AMM TASK 32-41-11-400-006).
Subtask 32-42-00-040-053-G ** ON A/C NOT FOR ALL (1) Remove the brake (Ref. AMM TASK 32-42-27-000-001).
NOTE: Install the nuts (8) and the washers (7) on the brake unit bolts (10) when you remove the brake unit.
(2) Clean the sleeves (4) and (12) and the electrical connector (9) of the brake temperature sensor. Apply two or three turns of the TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.): - around the sleeves (4) and (12),
- around the electrical connector (9) of the brake temperature sensor.
- around the tape on the sleeves (4) and (12),
- around the tape on the electrical connector (9).
NOTE: Make sure that the lockwire cannot rub when the landing gear operates.
(5) Remove the J47779 PROTECTIVE CONE from the wheel axle (6). (6) Install the main landing-gear wheel (Ref. AMM TASK 32-41-11-400-006).
D. Deactivation with the Brake Removal
(1) Remove the brake (Ref. AMM TASK 32-42-27-000-001).
(6) Install the main landing-gear wheel (Ref. AMM TASK 32-41-11-400-006).
Subtask 32-42-00-040-058-A (1) Remove the brake (Ref. AMM TASK 32-42-27-000-001).
NOTE: Install the nuts (8) and the washers (7) on the brake unit bolts (10) when you remove the brake unit.
(2) Clean the sleeves (4) and (12) and the electrical connector (9) of the brake temperature sensor. Apply two or three turns of the TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.): - around the sleeves (4) and (12),
- around the electrical connector (9) of the brake temperature sensor.
- around the tape on the sleeves (4) and (12),
- around the tape on the electrical connector (9).
NOTE: Make sure that the lockwire cannot rub when the landing gear operates.
(5) Remove the Q47323-1 GUIDE CONE from the wheel axle (6). (6) Install the main landing-gear wheel (Ref. AMM TASK 32-41-11-400-006).
E. Disconnect the flexible hoses from the normal and alternate braking system to do the deactivation of the wheel brake because of a leak
(1) Depressurize the Green and Yellow hydraulic reservoirs (Ref. AMM TASK 29-14-00-614-001).
(2) Removal of the normal and alternate braking-system flexible-hoses that have leaks
(a) If you find a leak on the normal braking flexible-hose (2):
1 Remove the flexible hose (2) with its quick-release connector from the brake self-sealing connector.
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related union.
3 Clean the brake hydraulic self-sealing-coupling and apply two or three turns of TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.).
(b) If you find no leak on the flexible hose (2), do not remove the hose and the quick-release connector from the brake unit.
(c) If you find a leak on the normal braking flexible-hose (5):
1 Remove the flexible hose (5) from the upper and the lower unions (Ref. AMM TASK 32-11-12-000-001).
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related unions.
(d) If you find no leak on the flexible hose (5), do not remove the hose.
(e) If you find a leak on the alternate braking flexible-hose (6):
1 Remove the flexible hose (6) from the flexible hose (1) connection and from the union (8) (Ref. AMM TASK 32-11-12-000-001).
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related unions to make sure that there are no leaks.
(f) If you find no leak on the flexible hose (6), do not remove the hose.
(g) If you find a leak on the alternate braking flexible-hose (1):
1 Remove the flexible hose (1) with its quick-release coupling from the brake hydraulic self-sealing-coupling (Ref. AMM TASK 32-11-12-000-001).
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related union.
3 Clean the brake hydraulic self-sealing-coupling and apply two or three turns of TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.).
(h) If you find no leak on the flexible hose (1), do not remove the hose and the quick-release coupling from the brake unit.
(3) Remove the bleed screw plug (3) from the related bleed screw (4).
(4) Connect a HOSE - VINYL to the bleed screws (4) and put the other end in a CONTAINER 5 L (1.32 USGAL) that contains Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(5) Release the remaining hydraulic pressure from the wheel brake as follows:
(b) Tighten the bleed screw (4).
(6) Disconnect the HOSE - VINYL.
(7) Install the bleed screw plug (3) on the bleed screw (4).
(8) Do the same procedure for the other bleed screw, if applicable.
(9) Do a pressure test after the installation of the blanking caps to make sure that there is no leak:
(a) For the normal braking-system deactivation, do the operational check of the normal braking system (Ref. AMM TASK 32-42-00-710-001). Make sure that there is no leak.
(b) For the alternate braking-system deactivation, do the operational check of the alternate braking system (Ref. AMM TASK 32-43-00-710-001). Make sure that there is no leak.
(10) Make sure that there are no signs of overstrain damage on the band clamps that connect the hydraulic pipes to the MLG.
(11) Make sure that there are no signs of damage at the mounting locations between the two ends of the hydraulic pipes and the MLG.
(12) Do a leak check at the blanking caps after each flight during the permitted repair intervals.
(13) 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 32-42-00-865-063-A (1) Depressurize the Green and Yellow hydraulic reservoirs (Ref. AMM TASK 29-14-00-614-001).
(2) Removal of the normal and alternate braking-system flexible-hoses that have leaks
(a) If you find a leak on the normal braking flexible-hose (2):
1 Remove the flexible hose (2) with its quick-release connector from the brake self-sealing connector.
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related union.
3 Clean the brake hydraulic self-sealing-coupling and apply two or three turns of TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.).
(b) If you find no leak on the flexible hose (2), do not remove the hose and the quick-release connector from the brake unit.
(c) If you find a leak on the normal braking flexible-hose (5):
1 Remove the flexible hose (5) from the upper and the lower unions (Ref. AMM TASK 32-11-12-000-001).
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related unions.
(d) If you find no leak on the flexible hose (5), do not remove the hose.
(e) If you find a leak on the alternate braking flexible-hose (6):
1 Remove the flexible hose (6) from the flexible hose (1) connection and from the union (8) (Ref. AMM TASK 32-11-12-000-001).
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related unions to make sure that there are no leaks.
(f) If you find no leak on the flexible hose (6), do not remove the hose.
(g) If you find a leak on the alternate braking flexible-hose (1):
1 Remove the flexible hose (1) with its quick-release coupling from the brake hydraulic self-sealing-coupling (Ref. AMM TASK 32-11-12-000-001).
2 Put a CAP - BLANKING P/N MS21914-6J or P/N MS21914-6K or P/N MS21914-6R or P/N MS21914-6S on the related union.
3 Clean the brake hydraulic self-sealing-coupling and apply two or three turns of TAPE - WIDE SELF-ADHESIVE - FABRIC 20 mm (0.79 in.) to 30 mm (1.18 in.).
(h) If you find no leak on the flexible hose (1), do not remove the hose and the quick-release coupling from the brake unit.
(3) Remove the bleed screw plug (3) from the related bleed screw (4).
(4) Connect a HOSE - VINYL to the bleed screws (4) and put the other end in a CONTAINER 5 L (1.32 USGAL) that contains Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(5) Release the remaining hydraulic pressure from the wheel brake as follows:
CAUTION:
ONLY LOOSEN THE BLEED SCREW TO RELEASE THE HYDRAULIC PRESSURE FROM THE WHEEL BRAKE. DO NOT DO A FULL BLEEDING AND DO NOT TOUCH THE PISTONS WITH YOUR HAND. IF YOU DO NOT OBEY THESE INSTRUCTIONS, DAMAGE TO THE BRAKE CAN OCCUR.
(a) Slowly loosen the bleed screw (4) to release the remaining hydraulic pressure from the wheel brake. (b) Tighten the bleed screw (4).
(6) Disconnect the HOSE - VINYL.
(7) Install the bleed screw plug (3) on the bleed screw (4).
(8) Do the same procedure for the other bleed screw, if applicable.
(9) Do a pressure test after the installation of the blanking caps to make sure that there is no leak:
(a) For the normal braking-system deactivation, do the operational check of the normal braking system (Ref. AMM TASK 32-42-00-710-001). Make sure that there is no leak.
(b) For the alternate braking-system deactivation, do the operational check of the alternate braking system (Ref. AMM TASK 32-43-00-710-001). Make sure that there is no leak.
(10) Make sure that there are no signs of overstrain damage on the band clamps that connect the hydraulic pipes to the MLG.
(11) Make sure that there are no signs of damage at the mounting locations between the two ends of the hydraulic pipes and the MLG.
(12) Do a leak check at the blanking caps after each flight during the permitted repair intervals.
(13) 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.
F. Make sure that this(these) circuit breaker(s) is(are) closed:
Subtask 32-42-00-860-069-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** 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 |
G. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) Pressurize the Yellow hydraulic system with the Yellow electric pump. (Ref. AMM TASK 29-24-00-863-001)
(3) On the panel 402VU, make sure that the A/SKID & NOSE WHEEL switch is set to ON.
Subtask 32-42-00-710-063-A (1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) Pressurize the Yellow hydraulic system with the Yellow electric pump. (Ref. AMM TASK 29-24-00-863-001)
(3) On the panel 402VU, make sure that the A/SKID & NOSE WHEEL switch is set to ON.
H. Tests
(1) Do this test:
(2) Do the functional test of the tachometer (Ref. AMM TASK 32-42-00-720-002) or as an alternative (Ref. AMM TASK 32-42-00-720-003) and (Ref. AMM TASK 32-42-00-710-001) .
Subtask 32-42-00-869-057-A (1) Do this test:
| ACTION | RESULT |
|---|---|
| 1.Fully push in the related brake pedals and hold them in this position. | Make sure that there are no leaks on the Yellow hydraulic-pressure line you disconnected. |
| 2.Release the brake pedals. | |
| 3.Pressurize the Green and Yellow hydraulic reservoirs (Ref. AMM TASK 29-14-00-614-002). | |
| 4.Pressurize the Green hydraulic system from the Yellow hydraulic system with the PTU (Ref. AMM TASK 29-23-00-863-001). Fully push in the related brake pedals and hold them in this position. | Make sure that there are no leaks on the Green hydraulic-pressure line you disconnected. |
| 5.Release the brake pedals. | |
NOTE: If you applied MMEL Item 32-42-06 before this brake deactivation, the functional test of the tachometer is not applicable.
I. System Consequences and Cockpit Effects in case of deactivation with the brake removal
This deactivation procedure can cause the Wheel page of the Systems Display to show the message XX at the applicable brake temperature indication.
5. Close-upThis deactivation procedure can cause the Wheel page of the Systems Display to show the message XX at the applicable brake temperature indication.
Subtask 32-42-00-860-070-A
A. Put the aircraft back to its initial configuration.
(1) Depressurize the Green and Yellow hydraulic systems (Ref. AMM TASK 29-10-00-864-001) (Ref. AMM TASK 29-10-00-864-002)
(2) Make sure that the level of the fluid in the Green and Yellow hydraulic reservoirs is correct. Add some fluid if it is necessary. (Ref. AMM TASK 12-12-29-611-001)
(3) De-energize the aircraft electrical network (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 main wheel brakes are deactivated.
(7) In the cockpit, install a PLACARD placard to tell the crew:
(1) Depressurize the Green and Yellow hydraulic systems (Ref. AMM TASK 29-10-00-864-001) (Ref. AMM TASK 29-10-00-864-002)
(2) Make sure that the level of the fluid in the Green and Yellow hydraulic reservoirs is correct. Add some fluid if it is necessary. (Ref. AMM TASK 12-12-29-611-001)
(3) De-energize the aircraft electrical network (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 main wheel brakes are deactivated.
(7) In the cockpit, install a PLACARD placard to tell the crew:
- that the brake unit No. 1 (2, 3, 4) is not operational or is removed.