DOC AIRBUS | AMM A320FFunctional Check to Monitor Internal Leak Rate of Braking System Components (Park Brake Selector Valve, Pressure Relief Valve and Alternate Brake Selector Valve)
TASK 32-44-00-720-004-A
Functional Check to Monitor Internal Leak Rate of Braking System Components (Park Brake Selector Valve, Pressure Relief Valve and Alternate Brake Selector Valve)
Refer to the MPD TASK: 324000-15
FUNCTIONAL CHECK TO MONITOR INTERNAL LEAK RATE OF BRAKING SYSTEM COMPONENTS.(PARK BRAKE SELECTOR VALVE, PRESSURE RELIEF VALVE AND ALTERNATE BRAKE SELECTOR VALVE)
You can also do this task for the leak test of the brake accumulator system during the related troubleshooting procedure.
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 32-44-00-865-058-A
Subtask 32-44-00-720-054-A ** ON A/C NOT FOR ALL
Subtask 32-44-00-942-055-A
[Rev.10 from 2021]
2026.04.01 00:49:26 UTC
Functional Check to Monitor Internal Leak Rate of Braking System Components (Park Brake Selector Valve, Pressure Relief Valve and Alternate Brake Selector Valve)
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 TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO 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:
PRESSURIZE ONLY THE HYDRAULIC SYSTEM(S) THAT IS (ARE) NECESSARY FOR THE TASK. ISOLATE THE OTHER HYDRAULIC SYSTEM(S) BEFORE YOU SUPPLY HYDRAULIC POWER TO THE AIRCRAFT.
WARNING:
MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.
1. Reason for the JobRefer to the MPD TASK: 324000-15
FUNCTIONAL CHECK TO MONITOR INTERNAL LEAK RATE OF BRAKING SYSTEM COMPONENTS.(PARK BRAKE SELECTOR VALVE, PRESSURE RELIEF VALVE AND ALTERNATE BRAKE SELECTOR VALVE)
You can also do this task for the leak test of the brake accumulator system during the related troubleshooting procedure.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | WARNING NOTICE(S) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 148 | MAIN GEAR WELL AND HYDRAULIC COMPARTMENT |
| 210 | CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD |
| 730 | LEFT MAIN LANDING GEAR & DOORS |
| 740 | RIGHT MAIN LANDING GEAR & DOORS |
| REFERENCE | DESIGNATION |
|---|---|
| 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 29-00-00-864-001-A | Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action |
| TASK 32-12-00-410-001-A | Close the Main Gear Doors after Access |
| TASK 32-44-11-200-001-A | Functional Check of Parking/Emergency Brake Accumulator by Reading the Charge Pressure on the Accumulator Gauge |
| TSM 32-44-00-810-808 | (for corrective action) |
Subtask 32-44-00-865-058-A
A. Make sure that this(these) circuit breaker(s) is(are) closed:
Subtask 32-44-00-860-061-A ** ON A/C NOT FOR ALL | 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 NOT FOR ALL | |||
| 121VU | HYDRAULIC/HYD POWER/Y | 3803GX | N30 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/HYD POWER/Y | 3803GX | N31 |
| ** ON A/C ALL | |||
| 123VU | Y HYD/ELEC/PUMP | 3802GX | AB06 |
B. Aircraft Maintenance Configuration
(1) On panel 400VU, make sure that the landing-gear control lever is in the DOWN position.
(2) On panel 110VU, make sure that the parking brake control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(5) Make sure that the Green and Yellow hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
(6) Do a check of the accumulator charging pressure and make sure that it is 100 bar (1450 psi) at 20 DEG.C (68 DEG.F) (Ref. AMM TASK 32-44-11-200-001).
(a) Do not close the main door of the right MLG.
(7) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch. Make sure that the OFF legend comes on.
(8) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(9) On panel 110VU, put the parking brake control-switch in the ON position.
(10) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch. Before you do other steps on the alternate braking system, wait a minimum of one hour.
(11) On panel 110VU, put the parking brake control-switch in the OFF position.
(12) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(13) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch.
Subtask 32-44-00-860-061-B ** ON A/C NOT FOR ALL (1) On panel 400VU, make sure that the landing-gear control lever is in the DOWN position.
(2) On panel 110VU, make sure that the parking brake control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(5) Make sure that the Green and Yellow hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
(6) Do a check of the accumulator charging pressure and make sure that it is 100 bar (1450 psi) at 20 DEG.C (68 DEG.F) (Ref. AMM TASK 32-44-11-200-001).
(a) Do not close the main door of the right MLG.
(7) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch. Make sure that the OFF legend comes on.
(8) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(9) On panel 110VU, put the parking brake control-switch in the ON position.
(10) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch. Before you do other steps on the alternate braking system, wait a minimum of one hour.
NOTE: This is to make sure that the fluid temperature is almost the same as the ambient temperature.
(a) Do not push the brake pedals during this time. (11) On panel 110VU, put the parking brake control-switch in the OFF position.
(12) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(13) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch.
B. Aircraft Maintenance Configuration
(1) On panel 400VU, make sure that the landing-gear control lever is in the DOWN position.
(2) On panel 110VU, make sure that the parking brake control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(5) Make sure that the Green and Yellow hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
(6) Do a check of the accumulator charging pressure and make sure that it is70 bar (1015 psi) at 20 DEG.C (68 DEG.F) (Ref. AMM TASK 32-44-11-200-001).
(a) Do not close the main door of the right MLG.
(7) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch. Make sure that the OFF legend comes on.
(8) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(9) On panel 110VU, put the parking brake control-switch in the ON position.
(10) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch. Before you do other steps on the alternate braking system, wait a minimum of one hour.
(11) On panel 110VU, put the parking brake control-switch in the OFF position.
(12) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(13) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch.
Subtask 32-44-00-860-061-C ** ON A/C NOT FOR ALL (1) On panel 400VU, make sure that the landing-gear control lever is in the DOWN position.
(2) On panel 110VU, make sure that the parking brake control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(5) Make sure that the Green and Yellow hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
(6) Do a check of the accumulator charging pressure and make sure that it is70 bar (1015 psi) at 20 DEG.C (68 DEG.F) (Ref. AMM TASK 32-44-11-200-001).
(a) Do not close the main door of the right MLG.
(7) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch. Make sure that the OFF legend comes on.
(8) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(9) On panel 110VU, put the parking brake control-switch in the ON position.
(10) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch. Before you do other steps on the alternate braking system, wait a minimum of one hour.
NOTE: This is to make sure that the fluid temperature is almost the same as the ambient temperature.
(a) Do not push the brake pedals during this time. (11) On panel 110VU, put the parking brake control-switch in the OFF position.
(12) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(13) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch.
B. Aircraft Maintenance Configuration
(1) On panel 400VU, make sure that the landing-gear control lever is in the DOWN position.
(2) On panel 110VU, make sure that the parking brake control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(5) Make sure that the Green and Yellow hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
(6) Do a check of the accumulator charging pressure and make sure that it is 80 bar (1160 psi) at 20 DEG.C (68 DEG.F) (Ref. AMM TASK 32-44-11-200-001).
(a) Do not close the main door of the right MLG.
(7) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch. Make sure that the OFF legend comes on.
(8) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(9) On panel 110VU, put the parking brake control-switch in the ON position.
(10) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch. Before you do other steps on the alternate braking system, wait a minimum of one hour.
(11) On panel 110VU, put the parking brake control-switch in the OFF position.
(12) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(13) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch.
Subtask 32-44-00-941-056-A (1) On panel 400VU, make sure that the landing-gear control lever is in the DOWN position.
(2) On panel 110VU, make sure that the parking brake control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(5) Make sure that the Green and Yellow hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
(6) Do a check of the accumulator charging pressure and make sure that it is 80 bar (1160 psi) at 20 DEG.C (68 DEG.F) (Ref. AMM TASK 32-44-11-200-001).
(a) Do not close the main door of the right MLG.
(7) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch. Make sure that the OFF legend comes on.
(8) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(9) On panel 110VU, put the parking brake control-switch in the ON position.
(10) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch. Before you do other steps on the alternate braking system, wait a minimum of one hour.
NOTE: This is to make sure that the fluid temperature is almost the same as the ambient temperature.
(a) Do not push the brake pedals during this time. (11) On panel 110VU, put the parking brake control-switch in the OFF position.
(12) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bar (2988 psi). The brake accumulator pressure is shown on the ACCU PRESS indication on the triple pressure indicator on panel 400VU.
(13) On overhead panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch.
C. Safety Precautions
(1) Put the WARNING NOTICE(S) in position to tell persons not to:
4. Procedure(1) Put the WARNING NOTICE(S) in position to tell persons not to:
- Pressurize the Green and Yellow hydraulic systems.
- Operate the landing-gear control lever.
Subtask 32-44-00-720-054-A ** ON A/C NOT FOR ALL
A. Functional Check to Monitor Internal Leak Rate of Braking System Components. (Park Brake Selector-Valve, Pressure Relief Valve and Alternate Brake Selector-Valve)
(1) Do not push the brake pedals during the functional check to monitor internal leak rate of braking system components like:
(3) If two pressure values out of the three pressure values measured are less than the minimum values, do a check of the system to find the leak TSM 32-44-00-810-808.
(4) If the ambient temperature is more than 40 deg.C (104.00 deg.F) and if two of the three pressure values measured are less than the minimum pressure values, do a second test. We recommend that you do the test at an ambient temperature near 20 deg.C (68.00 deg.F).
Subtask 32-44-00-720-054-B ** ON A/C NOT FOR ALL (1) Do not push the brake pedals during the functional check to monitor internal leak rate of braking system components like:
- Park brake selector-valve
- Pressure relief valve
- Alternate brake selector-valve.
| ------------------ ------------------ Tamb | Plimit --------- After 30min --------- bar | Plimit --------- After 30min --------- PSI | Plimit --------- After 45min --------- bar | Plimit --------- After 45min --------- PSI | Plimit --------- After 60min --------- bar | Plimit -------- After 60min -------- PSI |
|---|---|---|---|---|---|---|
| Tamb > 20 deg.C (Tamb > 68 deg.F) | 152 | 2200 | 141 | 2050 | 131 | 1900 |
| 0 < Tamb < 20 deg.C (32 < Tamb < 68 deg.F) | 159 | 2300 | 148 | 2150 | 138 | 2000 |
| -10 < Tamb < 0 deg.C (14 < Tamb < 32 deg.F) | 176 | 2550 | 165 | 2400 | 159 | 2300 |
| Tamb < -10 deg.C (Tamb < 14 deg.F) | 183 | 2650 | 176 | 2550 | 169 | 2450 |
(4) If the ambient temperature is more than 40 deg.C (104.00 deg.F) and if two of the three pressure values measured are less than the minimum pressure values, do a second test. We recommend that you do the test at an ambient temperature near 20 deg.C (68.00 deg.F).
A. Functional Check to Monitor Internal Leak Rate of Braking System Components. (Park Brake Selector-Valve, Pressure Relief Valve and Alternate Brake Selector-Valve)
(1) Do not push the brake pedals during the functional check to monitor internal leak rate of braking system components like:
(3) If two pressure values out of the three pressure values measured are less than the minimum values, do a check of the system to find the leak TSM 32-44-00-810-808.
(4) If the ambient temperature is more than 40 deg.C (104.00 deg.F) and if two of the three pressure values measured are less than the minimum pressure values, do a second test. We recommend that you do the test at an ambient temperature near 20 deg.C (68.00 deg.F).
Subtask 32-44-00-720-054-C ** ON A/C NOT FOR ALL (1) Do not push the brake pedals during the functional check to monitor internal leak rate of braking system components like:
- Park brake selector-valve
- Pressure relief valve
- Alternate brake selector-valve.
| ------------------ ------------------ Tamb | Plimit --------- After 30min --------- bar | Plimit --------- After 30min --------- PSI | Plimit --------- After 45min --------- bar | Plimit --------- After 45min --------- PSI | Plimit --------- After 60min --------- bar | Plimit -------- After 60min -------- PSI |
|---|---|---|---|---|---|---|
| Tamb > 20 deg.C (Tamb > 68 deg.F) | 138 | 2000 | 124 | 1800 | 114 | 1650 |
| 0 < Tamb < 20 deg.C (32 < Tamb < 68 deg.F) | 145 | 2100 | 134 | 1950 | 124 | 1800 |
| (-10 < Tamb < 0 deg.C) (14 < Tamb < 32 deg.F) | 165 | 2400 | 152 | 2200 | 145 | 2100 |
| Tamb < -10 deg.C (Tamb < 14 deg.F) | 176 | 2550 | 169 | 2450 | 159 | 2300 |
(4) If the ambient temperature is more than 40 deg.C (104.00 deg.F) and if two of the three pressure values measured are less than the minimum pressure values, do a second test. We recommend that you do the test at an ambient temperature near 20 deg.C (68.00 deg.F).
A. Functional Check to Monitor Internal Leak Rate of Braking System Components. (Park Brake Selector-Valve, Pressure Relief Valve and Alternate Brake Selector-Valve)
(1) Do not push the brake pedals during the functional check to monitor internal leak rate of braking system components like:
(3) If two pressure values out of the three pressure values measured are less than the minimum values, do a check of the system to find the leak TSM 32-44-00-810-808.
(4) If the ambient temperature is more than 40 deg.C (104.00 deg.F) and if two of the three pressure values measured are less than the minimum pressure values, do a second test. We recommend that you do the test at an ambient temperature near 20 deg.C (68.00 deg.F).
Subtask 32-44-00-860-062-A (1) Do not push the brake pedals during the functional check to monitor internal leak rate of braking system components like:
- Park brake selector-valve
- Pressure relief valve
- Alternate brake selector-valve.
| ------------------------------------------------------------------------------- |
| ! ! PARKING BRAKE NOT APPLIED ! |
| ! !----------------------------------------------------------! |
| ! ! After 30min ! After 45min ! After 60min ! |
| ! !-------------------!-------------------!------------------! |
| ! ! bar ! PSI ! bar ! PSI ! bar ! PSI ! |
| ------------------------------------------------------------------------------- |
| ! Plimit ! 190 ! 2750 ! 185 ! 2700 ! 182 ! 2650 ! |
| ------------------------------------------------------------------------------- |
(3) If two pressure values out of the three pressure values measured are less than the minimum values, do a check of the system to find the leak TSM 32-44-00-810-808.
(4) If the ambient temperature is more than 40 deg.C (104.00 deg.F) and if two of the three pressure values measured are less than the minimum pressure values, do a second test. We recommend that you do the test at an ambient temperature near 20 deg.C (68.00 deg.F).
B. Aircraft Maintenance Configuration
(1) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch.
(a) Make sure that the OFF legend goes off.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
Subtask 32-44-00-410-054-A (1) On overhead panel 40VU, push and release the PTU/AUTO pushbutton switch.
(a) Make sure that the OFF legend goes off.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
C. Close Access
(1) Close the main door of the right MLG (Ref. AMM TASK 32-12-00-410-001).
(2) Make sure that the work area is clean and clear of tools and other items.
5. Close-up(1) Close the main door of the right MLG (Ref. AMM TASK 32-12-00-410-001).
(2) Make sure that the work area is clean and clear of tools and other items.
Subtask 32-44-00-942-055-A
A. Removal of Equipment
(1) Remove the WARNING NOTICE(S).
(2) Remove all the fixtures, tools, test and support equipment used during this procedure.
(1) Remove the WARNING NOTICE(S).
(2) Remove all the fixtures, tools, test and support equipment used during this procedure.