Installation of the Pressure-Off Brake of the Flap Power Control Unit
TASK 27-54-52-400-001-A
Installation of the Pressure-Off Brake of the Flap Power Control Unit
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Expendable Parts
D. Referenced Information
3. Job Set-up
Subtask 27-54-52-860-054-A
Subtask 27-54-52-860-052-A
(2) Install the new AIPC 27-54-51-01-070 PACKING (4) to the POB (41).
(3) Install the new AIPC 27-54-51-01-150 RETAINERS (12) and the new AIPC 27-54-51-01-160 PACKINGS (13) on the transfer tubes (14).
(4) Install the new AIPC 27-54-51-01-190 RETAINERS (31) and the new AIPC 27-54-51-01-200 PACKINGS (32) on the transfer tube (33).
(5) Carefully apply Silicone base Grease-- Paste - (Material No.03JAB1) to all the grooves of the transfer tubes (14) and (33).
(6) Put the transfer tubes (14),(33) in their related holes in the valve block assembly (23).
(7) Safety the transfer tubes (14),(33) with the new AIPC 27-54-51-01-140 LOCKING WASHERS (21) and the new AIPC 27-54-51-01-180 RETAINING RING (30).
(8) Install the POB (41) with the hydraulic motor (7) on the valve block assembly (23):
(a) Apply Mineral Oil base Grease-Anti-seize Lithium Thickened System (Material No.03FCC2) to the threads of the bolts (6).
(b) Carefully install the hydraulic motor (7) on the transfer tubes (14) of the valve block assembly (23).
(c) Carefully install the POB (41) on the transfer tube (33).
(d) Attach the POB (41) to the hydraulic motor (7) with the washers (5) and the bolts (6).
(e) TORQUE the bolts (6) to between 0.96 and 0.87 m.daN (84.96 and 76.99 lbf.in )
.
(9) Install the POB (41), the hydraulic motor (7) and the valve block assembly (23):
(a) Apply Mineral Oil base Grease-Anti-seize Lithium Thickened System (Material No.03FCC2) to the threads of the studs (42) and to the threads of the bolts (3).
(b) Install the POB (41), the hydraulic motor (7) and the valve block assembly (23) together to the differential gearbox (40).
(c) Attach the POB (41) and the valve block assembly (23) to the differential gearbox (40) with:
.
(10) Do a bonding test between the main bonding point of the power control unit and the:
(11) Connect the hydraulic lines.
(a) Remove the blanking caps and the blanking plugs from the line ends (8),(10),(11) and from the PCU (1).
(b) Make sure that the hydraulic line end-fittings are serviceable.
(c) Apply Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) to the threads of the line end-fittings.
(d) Connect the case drain line (8).
(e) TORQUE the union nut of the case drain line (8) to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft )
.
(f) Connect the seal drain line (10) and attach it with the new TIE WRAP (9).
(g) Connect the hydraulic lines (11).
(h) TORQUE the union nuts of the hydraulic lines (11) to between 5.9 and 5.4 m.daN (43.51 and 39.82 lbf.ft )
.
(12) Connect the electrical connector.
(a) Remove the blanking caps from the electrical connector (22).
(b) Make sure that all the electrical connections are clean and in the correct condition.
(c) Connect the electrical connector (22) to the valve block assembly (23).
Subtask 27-54-52-860-051-A
Subtask 27-54-52-860-053-A
[Rev.10 from 2021]
2026.03.31 23:54:18 UTC
Installation of the Pressure-Off Brake of the Flap Power Control Unit
WARNING:
OBEY THE HYDRAULIC SAFETY PROCEDURES.
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:
PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:
- THE FLIGHT CONTROLS
- THE FLIGHT CONTROL SURFACES
- THE LANDING GEAR AND THE RELATED DOORS
- COMPONENTS THAT MOVE.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE |
| No specific | 1 | CONTAINER 5 L (1.32 USGAL) |
| No specific | AR | TIE WRAP |
| No specific | 1 | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 0.96 and 0.87 m.daN (84.96 and 76.99 lbf.in ) ![]() | |
| No specific | Torque wrench: range to between 1.54 and 1.40 m.daN (11.36 and 10.32 lbf.ft ) ![]() | |
| No specific | Torque wrench: range to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft ) ![]() | |
| No specific | Torque wrench: range to between 5.9 and 5.4 m.daN (43.51 and 39.82 lbf.ft ) ![]() | |
| 98D27803000000 | 1 | LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.02ABA1) | Phosphate Ester Hydraulic Fluid-General Power - - |
| (Material No.03FCC2) | Mineral Oil base Grease-Anti-seize Lithium Thickened System |
| (Material No.03JAB1) | Silicone base Grease-- Paste - |
| (Material No.03QBA1) | Dry lubricant-General Assembly - - |
| (Material No.06LGB1) | Non Hardening Jointing Putty-- Electrical Conductive - |
| (Material No.08BAA9) | Non Aqueous Cleaner-General - - |
| (Material No.14FAB1) | Abrasive-- Scotch Brite Pads - |
| (Material No.14SBA1) | Textile-Lint free Cotton - |
| (Material No.14VGE1) | Individual Compound-- Zinc Powder - |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 4 | PACKING | AIPC 27-54-51-01-070 |
| 21 | LOCKING WASHERS | AIPC 27-54-51-01-140 |
| 12 | RETAINERS | AIPC 27-54-51-01-150 |
| 13 | PACKINGS | AIPC 27-54-51-01-160 |
| 30 | RETAINING RING | AIPC 27-54-51-01-180 |
| 31 | RETAINERS | AIPC 27-54-51-01-190 |
| 32 | PACKINGS | AIPC 27-54-51-01-200 |
| 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 27-00-00-080-002-A | Removal of the Flap/Slat Control-Lever Locking Tool (98D27803000000) |
| TASK 27-00-00-480-002-A | Installation of the Flap/Slat Control-Lever Locking Tool (98D27803000000) |
| TASK 27-50-00-480-802-A | Installation/Removal of the Check Pin at Track 1 |
| TASK 27-50-00-866-009-A | Retraction of the Flaps on the Ground |
| TASK 27-50-00-866-009-A-01 | Retraction of the Flaps/Slats on the Ground |
| TASK 27-54-00-710-001-A | Operational Test of the Flap System |
| TASK 29-00-00-864-001-A | Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action |
| 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 32-12-00-410-001-A | Close the Main Gear Doors after Access |
Subtask 27-54-52-860-054-A
A. Aircraft Maintenance Configuration
(1) Make sure that the flaps are retracted to the 0 degree position (Ref. AMM TASK 27-50-00-866-009).
(2) Make sure that the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION is installed (Ref. AMM TASK 27-00-00-480-002) on the slat/flap control lever.
(3) Make sure that the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE is in position at the main gear main door opening.
(4) Make sure that the Green and Yellow hydraulic systems are depressurized and put them in the maintenance configuration (Ref. AMM TASK 29-00-00-864-001).
(5) Make sure that the reservoirs of the Green and Yellow hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(6) Make sure that the WARNING NOTICE(S) is in position to tell persons not to pressurize the hydraulic systems.
(7) Put a CONTAINER 5 L (1.32 USGAL) in position below the Power Control Unit (PCU) (1).
(8) Make sure that the check pins are in position at the left and right flap tracks 1 (Ref. AMM TASK 27-50-00-480-802).
Subtask 27-54-52-865-051-A (1) Make sure that the flaps are retracted to the 0 degree position (Ref. AMM TASK 27-50-00-866-009).
(2) Make sure that the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION is installed (Ref. AMM TASK 27-00-00-480-002) on the slat/flap control lever.
(3) Make sure that the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE is in position at the main gear main door opening.
(4) Make sure that the Green and Yellow hydraulic systems are depressurized and put them in the maintenance configuration (Ref. AMM TASK 29-00-00-864-001).
(5) Make sure that the reservoirs of the Green and Yellow hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(6) Make sure that the WARNING NOTICE(S) is in position to tell persons not to pressurize the hydraulic systems.
(7) Put a CONTAINER 5 L (1.32 USGAL) in position below the Power Control Unit (PCU) (1).
(8) Make sure that the check pins are in position at the left and right flap tracks 1 (Ref. AMM TASK 27-50-00-480-802).
B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
4. Procedure| PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B07 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B02 |
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/FLP/CTL AND/MONG/SYS2 | 8CV | Q21 |
Subtask 27-54-52-860-052-A
A. Preparation for Installation
(1) Do an inspection of the component interfaces and the adjacent area.
(2) Use a lint-free cotton cloth Textile-Lint free Cotton - (Material No.14SBA1) and the Non Aqueous Cleaner-General - - (Material No.08BAA9) to clean the:
(4) Apply a quantity of the prepared mixture or apply Non Hardening Jointing Putty to the related electrical bonding areas (refer to the related figure):
(a) Make sure that you apply the material on the mating areas on the differential gearbox and on the removed POB.
(b) Make sure that you apply the material on the mating areas on the removed POB and on the removed valve block (23CV or 24CV).
(c) Make sure that you apply the material on the mating areas on the removed POB and on the removed hydraulic motor.
(5) Apply the Dry lubricant-General Assembly - - (Material No.03QBA1) to the splined surfaces.
(6) Apply Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) to the new packing (4).
(7) If installed, remove the screw, the protection cap and the packing from the replacement POB.
Subtask 27-54-52-420-050-A (1) Do an inspection of the component interfaces and the adjacent area.
(2) Use a lint-free cotton cloth Textile-Lint free Cotton - (Material No.14SBA1) and the Non Aqueous Cleaner-General - - (Material No.08BAA9) to clean the:
- mating areas of the POB
- mating areas of the hydraulic motor
- mating areas of the valve block
- mating areas of the differential gearbox
(4) Apply a quantity of the prepared mixture or apply Non Hardening Jointing Putty to the related electrical bonding areas (refer to the related figure):
(a) Make sure that you apply the material on the mating areas on the differential gearbox and on the removed POB.
(b) Make sure that you apply the material on the mating areas on the removed POB and on the removed valve block (23CV or 24CV).
(c) Make sure that you apply the material on the mating areas on the removed POB and on the removed hydraulic motor.
(5) Apply the Dry lubricant-General Assembly - - (Material No.03QBA1) to the splined surfaces.
(6) Apply Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) to the new packing (4).
(7) If installed, remove the screw, the protection cap and the packing from the replacement POB.
CAUTION:
USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT HYDRAULIC LINES ON UNIONS. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL LOOSEN OR TIGHTEN THE UNION TOO MUCH.
CAUTION:
YOU MUST INSTALL HYDRAULIC TUBES WITH HYDRAULIC FLUID AS LUBRICANT.
CAUTION:
DO NOT USE POINTED, SHARP OR METAL TOOLS TO REMOVE AND INSTALL PACKINGS OR RETAINERS. ALSO MAKE SURE THAT YOU USE THE CORRECT TOOLS TO REMOVE AND INSTALL LOCKING WASHERS OR RETAINING RINGS. IF YOU DO NOT USE THE CORRECT TOOLS, YOU CAN EASILY CAUSE DAMAGE TO THESE COMPONENTS.
CAUTION:
YOU MUST BE CAREFUL WHEN YOU MOVE THE TRANSFER TUBES AND THE ADJACENT COMPONENTS. IF YOU ARE NOT CAREFUL, YOU CAN EASILY CAUSE DAMAGE TO THEM.
B. Installation of the Pressure-Off Brake NOTE: The installation procedure for the POB at the valve block 23CV is given. The installation procedure for the POB at the valve block 24CV is almost the same. The differences in the procedures are given.
(1) Do a visual check of the transfer tubes. If you find small scratches, use Abrasive-- Scotch Brite Pads - (Material No.14FAB1) to remove them. This will make sure that the condition of the valve block transfer holes is satisfactory. (2) Install the new AIPC 27-54-51-01-070 PACKING (4) to the POB (41).
(3) Install the new AIPC 27-54-51-01-150 RETAINERS (12) and the new AIPC 27-54-51-01-160 PACKINGS (13) on the transfer tubes (14).
(4) Install the new AIPC 27-54-51-01-190 RETAINERS (31) and the new AIPC 27-54-51-01-200 PACKINGS (32) on the transfer tube (33).
(5) Carefully apply Silicone base Grease-- Paste - (Material No.03JAB1) to all the grooves of the transfer tubes (14) and (33).
(6) Put the transfer tubes (14),(33) in their related holes in the valve block assembly (23).
(7) Safety the transfer tubes (14),(33) with the new AIPC 27-54-51-01-140 LOCKING WASHERS (21) and the new AIPC 27-54-51-01-180 RETAINING RING (30).
(8) Install the POB (41) with the hydraulic motor (7) on the valve block assembly (23):
(a) Apply Mineral Oil base Grease-Anti-seize Lithium Thickened System (Material No.03FCC2) to the threads of the bolts (6).
(b) Carefully install the hydraulic motor (7) on the transfer tubes (14) of the valve block assembly (23).
(c) Carefully install the POB (41) on the transfer tube (33).
(d) Attach the POB (41) to the hydraulic motor (7) with the washers (5) and the bolts (6).
(e) TORQUE the bolts (6) to between 0.96 and 0.87 m.daN (84.96 and 76.99 lbf.in )
. (9) Install the POB (41), the hydraulic motor (7) and the valve block assembly (23):
(a) Apply Mineral Oil base Grease-Anti-seize Lithium Thickened System (Material No.03FCC2) to the threads of the studs (42) and to the threads of the bolts (3).
(b) Install the POB (41), the hydraulic motor (7) and the valve block assembly (23) together to the differential gearbox (40).
(c) Attach the POB (41) and the valve block assembly (23) to the differential gearbox (40) with:
- the washers (2),
- the bolts (3),
- the washers (25),
- the nuts (24).
. (10) Do a bonding test between the main bonding point of the power control unit and the:
- POB flange,
- hydraulic motor flange,
- valve block assembly flange.
(11) Connect the hydraulic lines.
(a) Remove the blanking caps and the blanking plugs from the line ends (8),(10),(11) and from the PCU (1).
(b) Make sure that the hydraulic line end-fittings are serviceable.
(c) Apply Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) to the threads of the line end-fittings.
(d) Connect the case drain line (8).
(e) TORQUE the union nut of the case drain line (8) to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft )
. (f) Connect the seal drain line (10) and attach it with the new TIE WRAP (9).
(g) Connect the hydraulic lines (11).
(h) TORQUE the union nuts of the hydraulic lines (11) to between 5.9 and 5.4 m.daN (43.51 and 39.82 lbf.ft )
. (12) Connect the electrical connector.
(a) Remove the blanking caps from the electrical connector (22).
(b) Make sure that all the electrical connections are clean and in the correct condition.
(c) Connect the electrical connector (22) to the valve block assembly (23).
C. Preparation for the Test
(1) Remove the check pins from the left and right flap tracks 1 (Ref. AMM TASK 27-50-00-480-802).
(2) Pressurize the reservoirs of the Green and Yellow hydraulic systems (Ref. AMM TASK 29-14-00-614-002).
(3) Make sure that the level of the fluid in the related hydraulic reservoir is correct. Add fluid as necessary (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
(4) Remove the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION (Ref. AMM TASK 27-00-00-080-002) from the slat/flap control lever.
(5) Remove the WARNING NOTICE(S).
(6) Make sure that the work area is clean and clear of tools and other items.
Subtask 27-54-52-865-052-A (1) Remove the check pins from the left and right flap tracks 1 (Ref. AMM TASK 27-50-00-480-802).
(2) Pressurize the reservoirs of the Green and Yellow hydraulic systems (Ref. AMM TASK 29-14-00-614-002).
(3) Make sure that the level of the fluid in the related hydraulic reservoir is correct. Add fluid as necessary (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
(4) Remove the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION (Ref. AMM TASK 27-00-00-080-002) from the slat/flap control lever.
(5) Remove the WARNING NOTICE(S).
(6) Make sure that the work area is clean and clear of tools and other items.
D. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 27-54-52-710-050-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B07 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B02 |
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/FLP/CTL AND/MONG/SYS2 | 8CV | Q21 |
E. Test
(1) Do the operational test of the flap system (Ref. AMM TASK 27-54-00-710-001).
(2) Make sure that there are no leaks and that no fluid comes out of the seal drain line (10).
5. Close-up(1) Do the operational test of the flap system (Ref. AMM TASK 27-54-00-710-001).
(2) Make sure that there are no leaks and that no fluid comes out of the seal drain line (10).
Subtask 27-54-52-860-053-A
A. Put the aircraft back to the serviceable condition.
(1) Make sure that the level of the fluid in the relevant hydraulic reservoir is correct. Add fluid as necessary (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
(2) Remove the container from below the PCU (1).
(3) Remove the access platform(s).
Subtask 27-54-52-410-050-A (1) Make sure that the level of the fluid in the relevant hydraulic reservoir is correct. Add fluid as necessary (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
(2) Remove the container from below the PCU (1).
(3) Remove the access platform(s).
Location of the Electrical Bonding Areas