W DOC AIRBUS | TSM A320F

Loss of the Brake-Accumulator Pressure with Parking Brake Set to On

TASK 32-45-00-810-801-A
Loss of the Brake-Accumulator Pressure with Parking Brake Set to On

1. Possible Causes
  • CTL VALVE-PARK BRK,ELEC. [72GG]
  • ACCU-BRK YELLOW PRESS [2582GM]
  • CHECK VALVE Y [3058GM]
  • BRAKE RELIEF VALVE [3067GM]
  • AUTOMATIC SEL-BRK [2576GM]
  • DUAL SHUTTLE VALVE-BRK YELLOW PRESS [2578GM]
  • MANIFOLD [3016GM]
  • VALVE-PARK BRK OPERATED [2579GM]
  • CTL VALVE-PARK BRK, ELEC [102GG]
  • SEL VALVE-ALTN BRK [99GG]
  • MANIFOLD-ALTN BRK, R [2852GM]
  • MANIFOLD-ALTN BRK, L [2853GM]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 32-43-00-810-830-A
Failure of the right BRK ALTN MANIFOLD
TSM TASK 32-43-00-810-831-A
Failure of the left BRK ALTN MANIFOLD
AMM 12-14-32-614-002
Nitrogen Filling of the Yellow Hydraulic System, Brake Pressure Accumulator
AMM 24-41-00-861-002
Energize the Aircraft Electrical Circuits from the External Power
AMM 29-00-00-910-003
General Removal and Installation Procedure of the Check Valves in the Hydraulic Systems
AMM 29-10-00-864-001
Depressurize the Green Hydraulic System
AMM 29-10-00-864-002
Depressurize the Yellow Hydraulic System
AMM 29-14-00-614-001
Depressurization of the Hydraulic Reservoirs
AMM 29-14-00-614-002
Pressurization of the Hydraulic Reservoirs through the Ground Connector
AMM 29-24-00-863-001
Pressurize the Yellow Hydraulic System with the Electric Pump
AMM 32-42-13-000-001
Removal of the Automatic Selector
AMM 32-42-13-400-001
Installation of the Automatic Selector
AMM 32-43-32-000-001
Removal of the Alternate-Brake Manifold
AMM 32-43-32-400-001
Installation of the Alternate-Brake Manifold
AMM 32-43-51-000-001
Removal of the Alternate Braking Selector Valve
AMM 32-43-51-400-001
Installation of the Alternate Braking Selector Valve
AMM 32-44-11-000-001
Removal of the Accumulator
AMM 32-44-11-200-001
Functional Check of Parking/Emergency Brake Accumulator by Reading the Charge Pressure on the Accumulator Gauge
AMM 32-44-11-400-001
Installation of the Accumulator
AMM 32-44-15-000-001
Removal of the Pressure Relief Valve
AMM 32-44-15-400-001
Installation of the Pressure Relief Valve
AMM 32-44-17-000-001
Removal of the Brake Manifold
AMM 32-44-17-400-001
Installation of the Brake Manifold
AMM 32-45-00-720-002
Functional Check of the Brake Accumulator System with the Parking Brake Applied
AMM 32-45-14-000-001
Removal of the Parking Brake Valve 2579GM
AMM 32-45-14-400-001
Installation of the Parking Brake Valve 2579GM
AMM 32-45-16-000-001
Removal of the Dual Shuttle Valve
AMM 32-45-16-400-001
Installation of the Dual Shuttle Valve
AMM 32-45-51-000-001
Removal of the Parking-Brake Electrical Control-Valve
AMM 32-45-51-400-001
Installation of the Parking-Brake Electrical Control-Valve
AMM 32-46-00-740-002
BITE Test of the BSCU - Ground Scanning
F Parking Brake System with Parking Brake Set to on ** ON A/C NOT FOR ALL
F Parking Brake System with Parking Brake Set to on ** ON A/C NOT FOR ALL
3. Fault Confirmation
Subtask 32-45-00-720-050-A ** ON A/C NOT FOR ALL
A. Test
   (1) Do the functional test of the brake accumulator system with the parking brake applied AMM 32-45-00-720-002.
Subtask 32-45-00-720-050-B ** ON A/C NOT FOR ALL
A. Test
   (1) On the R CENTER INSTRUMENT panel 400VU, make sure that the landing gear control lever is in the DOWN position.
   (2) On the RUD TRIM/PARKING BRK panel 110VU, make sure that the PARKING BRK control switch is in the ON position.
   (3) Make sure that the CAPT and F/O brake pedals are released.
   (4) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
   (5) Make sure that the Green and Yellow hydraulic systems are depressurized AMM 29-10-00-864-001 and AMM 29-10-00-864-002.
   (6) On the HYD/FUEL panel 40VU, push and release the YELLOW/ELEC PUMP pushbutton switch to pressurize the brake accumulator system to 206 bars (2988 psi) AMM 29-24-00-863-001.
   (7) Wait for ten seconds then do the BITE test of the BSCU (GROUND SCANNING) AMM 32-46-00-740-002.
     (a) If the test gives the maintenance message BRK ALTN MANIFOLD LEFT (2853GM):
     (b) If the test gives the maintenance message BRK ALTN MANIFOLD RIGHT (2852GM):
     (c) If the maintenance message BRK ALTN MANIFOLD LEFT (2853GM) or BRK ALTN MANIFOLD RIGHT (2852GM) is not shown:
  • Continue the trouble shooting procedure.
   (8) Do the functional test of the brake accumulator system with the parking brake applied AMM 32-45-00-720-002.
4. Fault Isolation
WARNING: BEFORE YOU DO THE CHECKS IN THIS PROCEDURE, ALWAYS CONNECT A DRAIN HOSE TO THE OPEN PORT. MAKE SURE THAT YOU POINT IT AWAY FROM YOU. IF THE COMPONENT IS DEFECTIVE, THERE CAN BE IMPORTANT LEAKAGE AT THE PORT. HYDRAULIC FLUID WILL THUS SPRAY OUT AT HIGH PRESSURE WHEN YOU PRESSURIZE THE HYDRAULIC SYSTEM. THIS WILL CAUSE INJURY TO YOU AND DAMAGE TO EQUIPMENT.
WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES.
NOTE: After all maintenance operations on the braking system such as hydraulic line disconnection/connection or component replacement, bleed from the brake units (Ref. AMM TASK 32-43-00-870-002).
NOTE: After disconnection of the hydraulic lines, it is important that you let the hydraulic pressure and leakage become stable (5 minutes minimum) before you make an estimate of component leakage.
Subtask 32-45-00-810-050-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
   (1) Do a check for leakage of the parking-brake control valve (72GG):
  • On the Yellow brake-system relief-valve (3067GM) operate the manual depressurization pushbutton to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • On the accumulator pressure gage (2585GM), make sure that the nitrogen pressure is correct AMM 32-44-11-200-001.
  • On the parking-brake control valve (72GG), disconnect the hydraulic line at port B.
  • Install a plug on the disconnected line.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
  • Do a check for hydraulic leakage of the parking-brake control valve (72GG) at port B.
     (a) If leakage is more than 20 drops/min:
     (b) If leakage is in the permitted tolerances:
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Connect the line at port B.
   (2) Do a check of the Yellow-pressure brake accumulator (2582GM)
  • On the Yellow-pressure brake accumulator (2582GM) release the nitrogen pressure.
  • Remove the ACCU-BRK YELLOW PRESS [2582GM] AMM 32-44-11-000-001.
  • In the accumulator, on the nitrogen side, do a check for hydraulic fluid.
     (a) If there is hydraulic fluid:
  • Collect and measure the volume of the hydraulic fluid.
       1 If the volume of the hydraulic fluid is more than 100 cm3 (6.10 in.3):
     (b) If there is no hydraulic fluid or if the volume of the hydraulic fluid is less than 100 cm3 (6.10 in.3):
WARNING: WHEN YOU DISCONNECT A LINE WITH THE SYSTEM PRESSURIZED, BE VERY CAREFUL TO LOOSEN THE PIPE-END FITTING GRADUALLY. IF THE COMPONENT IS DEFECTIVE, THERE CAN BE IMPORTANT LEAKAGE AT THE PORT. HYDRAULIC FLUID WILL THUS SPRAY OUT AT HIGH PRESSURE. THIS WILL CAUSE INJURY TO YOU AND DAMAGE TO EQUIPMENT.
   (3) Do a check of the Yellow brake-system check-valve (3058GM):
  • Inflate the accumulator with nitrogen AMM 12-14-32-614-002.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2987.7766 psi) and stop the pump.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • On the parking brake manifold (3016GM), disconnect the port A.
  • Install a plug on the disconnected hydraulic line.
  • Make sure that there is no leakage.
     (a) If there is a leakage :
     (b) If there is no leakage:
  • Connect the line at port A.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to Release the accumulator pressure.
   (4) Do a check for leakage of the Yellow brake-system relief-valve (3067GM):
  • On the brake manifold (3016GM) disconnect the lines at ports D, E, F and G.
  • Install a plug at ports E, F, and G and a plug on the disconnected hydraulic lines.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • On the brake manifold (3016GM) do a check for hydraulic leakage at port D.
     (a) If leakage is more than 10 drops/min:
     (b) If leakage is in the permitted tolerances:
  • Connect the line at port D.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Remove the plugs from ports E, F and G and from the disconnected hydraulic lines.
  • Connect the lines at ports E, F, and G.
   (5) Do a check for leakage of the brake automatic selector (2576GM)
  • On the brake automatic selector (2576GM) disconnect the line at port H and install a plug on the disconnected hydraulic line.
  • In the cockpit, set the PARKING BRK control switch to OFF.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Set the PARKING BRK control switch to ON.
  • On the brake automatic selector (2576GM), do a check for leaks at port H.
     (a) If leakage at port H is more than 60 drops/min:
     (b) If leakage at port H is in the permitted tolerances:
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Connect the line at port H.
   (6) Do a check for leakage of the brake Yellow-pressure dual shuttle-valve (2578GM)
  • Make sure that the accumulator pressure is released (operation of the manual depressurization pushbutton on the Yellow brake-system relief-valve (3067GM)).
  • On the dual shuttle-valve (2578GM) disconnect the lines at ports D and E and install a plug on the disconnected hydraulic lines.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump. In the cockpit, make sure that the PARKING BRK control switch is at ON.
  • On the dual shuttle-valve (2578GM) do a check for leaks at ports D and E.
     (a) If leakage at port D or port E is more than 2 drops/min:
     (b) If leakage at ports D and E is in the permitted tolerances:
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Connect the lines at ports D and E.
   (7) Do a check of the parking brake manifold (3016GM):
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
     (a) If the fault continues:
WARNING: WHEN YOU DISCONNECT A LINE WITH THE SYSTEM PRESSURIZED, BE VERY CAREFUL TO LOOSEN THE PIPE-END FITTING GRADUALLY. IF THE COMPONENT IS DEFECTIVE, THERE CAN BE IMPORTANT LEAKAGE AT THE PORT. HYDRAULIC FLUID WILL THUS SPRAY OUT AT HIGH PRESSURE. THIS WILL CAUSE INJURY TO YOU AND DAMAGE TO EQUIPMENT.
   (8) Do a check of the PARK BRK OPERATED VALVE (2579GM)
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • On the PARK BRK OPERATED VALVE (2579GM), disconnect the hydraulic line at port B.
  • Install a plug on the disconnected line.
  • Make sure that there is no leakage at port B.
     (a) If there is a leakage :
Subtask 32-45-00-810-050-B ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
   (1) Do a check for leakage of the parking-brake control valve (102GG):
  • On the Yellow brake-system relief-valve (3067GM) operate the manual depressurization pushbutton to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • On the accumulator pressure gage (2585GM), make sure that nitrogen pressure is correct AMM 32-44-11-200-001.
  • On the parking-brake selector valve (102GG) at port B (return line), disconnect the hydraulic line.
  • Install a plug on the disconnected line.
  • On the Yellow hydraulic sytem, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
  • Do a check for hydraulic leakage of the parking-brake control valve (102GG) at port B.
     (a) If the leakage is more than 20 cm3/min during the first six minutes and more than 1 cm3/min after this time:
     (b) If leakage is in the permitted tolerances:
  • Put the parking brake control switch (73GG) in the OFF position.
  • Operate the manual depressurization pushbutton of the relief-valve (3067GM) to release the accumulator pressure.
  • Connect the line at port B.
   (2) Do a check of the Yellow-pressure brake accumulator (2582GM):
  • On the Yellow-pressure brake accumulator (2582GM) release the nitrogen pressure.
  • Remove the Yellow-pressure brake accumulator (2582GM) AMM 32-44-11-000-001.
  • In the accumulator, on the nitrogen side, do a check for hydraulic fluid.
     (a) If there is hydraulic fluid:
  • Collect and measure the volume of the hydraulic fluid.
       1 If the volume of the hydraulic fluid is more than 100 cm3 (6.10 in.3):
  • Replace the ACCU-BRK YELLOW PRESS [2582GM] .
     (b) If there is no hydraulic fluid or if the volume of the hydraulic fluid is less than 100 cm3 (6.10 in.3):
WARNING: WHEN YOU DISCONNECT A LINE WITH THE SYSTEM PRESSURIZED, BE VERY CAREFUL TO LOOSEN THE PIPE-END FITTING GRADUALLY. IF THE COMPONENT IS DEFECTIVE, THERE CAN BE IMPORTANT LEAKAGE AT THE PORT. HYDRAULIC FLUID WILL THUS SPRAY OUT AT HIGH PRESSURE. THIS WILL CAUSE INJURY TO YOU AND DAMAGE TO EQUIPMENT.
   (3) Do a check of the CHECK VALVE-BRK SYS, Y (3058GM):
  • Inflate the accumulator with nitrogen AMM 12-14-32-614-002.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • On the parking brake manifold (3016GM), disconnect the port A.
  • Install a plug on the disconnected hydraulic line.
  • Make sure that there is no leakage.
     (a) If there is a leakage :
     (b) If there is no leakage:
  • Connect the line at port A.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
   (4) On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
   (5) If the fault continues:
  • Put the parking-brake control switch (73GG) in the OFF position.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Replace the BRAKE RELIEF VALVE [3067GM] AMM 32-44-15-000-001 AMM 32-44-15-400-001.
   (6) On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
   (7) If the fault continues:
  • Put the parking-brake control switch (73GG) in the OFF position.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Replace the SEL VALVE-ALTN BRK [99GG] AMM 32-43-51-000-001 AMM 32-43-51-400-001.
   (8) On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2987.7766 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
   (9) If the fault continues:
  • Put the parking-brake control switch (73GG) in the OFF position.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Replace the MANIFOLD [3016GM] AMM 32-44-17-400-001 AMM 32-44-17-400-001.
   (10) On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
   (11) If the fault continues, do a check of the ALT BRK MANIFOLD RH (2852GM):
  • Put the parking-brake control switch (73GG) in the OFF position.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Disconnect the hydraulic line (supply line) at the T level between the PARK BRK SELECTOR VALVE (102GG) port C and the ALT BRK MANIFOLD LH (2853GM) port D.
  • Install a plug on the T fitting and on the ALT BRK MANIFOLD LH (2853GM) supply line to check only the right side of the system.
  • Disconnect the hydraulic line at port C (return port) of the ALT BRK MANIFOLD (2852GM).
  • Install a plug on the disconnected hydraulic line.
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2987.7766 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
     (a) If leakage is more than 0.25 cm3/min:
     (b) If leakage is in the permitted tolerances:
  • Put the parking-brake control switch (73GG) in the OFF position.
  • Operate the manual depressurization pushbutton of the Yellow brake-system relief-valve (3067GM) to release the accumulator pressure.
  • On the Yellow hydraulic system, depressurize the hydraulic reservoir AMM 29-14-00-614-001.
  • Remove the plug on the T fitting and on the ALT BRK MANIFOLD LH (2853GM) supply line.
  • Connect the ALT BRK MANIFOLD LH (2853GM) hydraulic line at the T level.
  • Connect the hydraulic line at port C (return port) of the ALT BRK MANIFOLD LH (2853GM).
  • On the Yellow hydraulic system, pressurize the hydraulic reservoir AMM 29-14-00-614-002.
  • Use the Yellow electric pump to pressurize the Yellow-pressure brake accumulator (2582GM) to 206 bar (2988 psi) and stop the pump.
  • Put the parking-brake control switch (73GG) in the ON position.
   (12) If the fault continues:
[Rev.8 from Aug 2018] 2026.04.04 04:31:44 UTC
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