Installation of the Valve Blocks of the Power Control Unit (Slat)
TASK 27-84-53-400-001-A
Installation of the Valve Blocks of the Power Control Unit (Slat)
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 27-84-53-860-055-A
Subtask 27-84-53-860-054-A
Subtask 27-84-53-860-056-A
[Rev.10 from 2021]
2026.03.31 23:57:44 UTC
Installation of the Valve Blocks of the Power Control Unit (Slat)
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:
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.
NOTE: The installation procedure for the valve block 25CV is given. The installation procedure for the valve block 26CV is almost the same. The differences in the procedures are given.
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 - HYDRAULIC FLUID RESISTANT |
| No specific | AR | TIE WRAP |
| No specific | AR | 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 ) ![]() | |
| 98D27504030001 | 1 | LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT |
| 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.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 - |
| (Material No.666400) | ELECOLIT 414 |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 4 | PACKING | AIPC 27-84-51-01-070 |
| 21 | LOCKING WASHERS | AIPC 27-84-51-01-140 |
| 12 | RETAINERS | AIPC 27-84-51-01-150 |
| 13 | PACKINGS | AIPC 27-84-51-01-160 |
| 30 | RETAINING RING | AIPC 27-84-51-01-180 |
| 31 | RETAINERS | AIPC 27-84-51-01-190 |
| 32 | PACKINGS | AIPC 27-84-51-01-200 |
| 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 27-50-00-000-003-A | Removal of the Lock-Torque Shaft - Flaps and Slats (98D27504030001) |
| TASK 27-80-00-866-005-A | Retracting the Slats on the Ground |
| TASK 27-84-00-710-001-A | Operational Test of the Slat 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 27-84-53-860-055-A
A. Aircraft Maintenance Configuration
(1) Make sure that the slats are in the 0 degree position (Ref. AMM TASK 27-80-00-866-005).
(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 opening of the main door of the main gear.
(4) Make sure that the Green and the Blue 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 the Blue hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(6) Make sure that the WARNING NOTICE(S) in position to tell persons not to pressurize the hydraulic systems.
(7) Make sure that the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT is installed to lock the left slat transmission.
(8) Make sure that the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT is installed to lock the right slat transmission.
(9) Make sure that a CONTAINER - HYDRAULIC FLUID RESISTANT is in position below the Power Control Unit (PCU) (1).
Subtask 27-84-53-865-051-A (1) Make sure that the slats are in the 0 degree position (Ref. AMM TASK 27-80-00-866-005).
(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 opening of the main door of the main gear.
(4) Make sure that the Green and the Blue 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 the Blue hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(6) Make sure that the WARNING NOTICE(S) in position to tell persons not to pressurize the hydraulic systems.
(7) Make sure that the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT is installed to lock the left slat transmission.
(8) Make sure that the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT is installed to lock the right slat transmission.
(9) Make sure that a CONTAINER - HYDRAULIC FLUID RESISTANT is in position below the Power Control Unit (PCU) (1).
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/SLT/CTL AND MONG/SYS1 | 5CV | B06 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/SLT/CTL AND MONG/SYS1 | 5CV | B01 |
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/SLT/CTL/SYS2 | 7CV | R21 |
Subtask 27-84-53-860-054-A
A. Preparation for Installation
(1) Do an inspection of the component interfaces and the adjacent area.
(2) Use a 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 Elecolit 414 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 (25CV or 26CV).
(c) Make sure that you apply the material on the mating areas on the removed POB and on the removed hydraulic motor.
(5) Apply 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).
Subtask 27-84-53-420-050-A (1) Do an inspection of the component interfaces and the adjacent area.
(2) Use a Textile-Lint free Cotton - (Material No.14SBA1) and the Non Aqueous Cleaner-General - - (Material No.08BAA9) to clean the:
- the mating areas of the hydraulic motor,
- the mating areas of the POB,
- the mating areas of the valve blocks
- the mating areas of the differential gearbox.
(4) Apply a quantity of the prepared mixture or apply Elecolit 414 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 (25CV or 26CV).
(c) Make sure that you apply the material on the mating areas on the removed POB and on the removed hydraulic motor.
(5) Apply 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).
B. Installation of the Valve Block
(2) Install the new AIPC 27-84-51-01-070 PACKING (4) on the POB (41).
(3) Install the new AIPC 27-84-51-01-150 RETAINERS (12) and the new AIPC 27-84-51-01-160 PACKINGS (13) on the transfer tubes (14).
(4) Install the new AIPC 27-84-51-01-190 RETAINERS (31) and AIPC 27-84-51-01-200 PACKINGS (32) the new 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 end of the transfer tubes (33), (14) in their related holes in the valve block assembly (23).
(7) Safety the transfer tubes (14), (33) with the new AIPC 27-84-51-01-140 LOCKING WASHERS (21) and the new AIPC 27-84-51-01-180 RETAINING RING (30).
(8) Install the valve block assembly (23) with the hydraulic motor (7) and the POB (41).
(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 valve block assembly (23) with the POB (41) and the hydraulic motor (7).
(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 valve block assembly (23), the hydraulic motor (7) and the POB (41) together to the differential gearbox (40).
(c) Attach the POB (41), the hydraulic motor (7) 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 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 seal drain line (10) and attach it with the new TIE WRAP (9).
(e) Connect the case drain line (8).
(f) 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 )
.
(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 (22).
(a) Remove the blanking caps from the electrical connectors (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 27-84-53-860-053-A 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.
(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 27-84-51-01-070 PACKING (4) on the POB (41).
(3) Install the new AIPC 27-84-51-01-150 RETAINERS (12) and the new AIPC 27-84-51-01-160 PACKINGS (13) on the transfer tubes (14).
(4) Install the new AIPC 27-84-51-01-190 RETAINERS (31) and AIPC 27-84-51-01-200 PACKINGS (32) the new 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 end of the transfer tubes (33), (14) in their related holes in the valve block assembly (23).
(7) Safety the transfer tubes (14), (33) with the new AIPC 27-84-51-01-140 LOCKING WASHERS (21) and the new AIPC 27-84-51-01-180 RETAINING RING (30).
(8) Install the valve block assembly (23) with the hydraulic motor (7) and the POB (41).
NOTE: You must install the valve block assembly (23) together with the POB (41) and the hydraulic motor (7).
(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 valve block assembly (23) with the POB (41) and the hydraulic motor (7).
(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 valve block assembly (23), the hydraulic motor (7) and the POB (41) together to the differential gearbox (40).
(c) Attach the POB (41), the hydraulic motor (7) 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 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 seal drain line (10) and attach it with the new TIE WRAP (9).
(e) Connect the case drain line (8).
(f) 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 )
. (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 (22).
(a) Remove the blanking caps from the electrical connectors (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 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT from the right slat transmission (Ref. AMM TASK 27-50-00-000-003).
(2) Remove the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT from the left slat transmission (Ref. AMM TASK 27-50-00-000-003).
(3) Pressurize the reservoirs of the Green and the Blue hydraulic systems (Ref. AMM TASK 29-14-00-614-002).
(4) Make sure that the level of 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).
(5) Remove the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION (Ref. AMM TASK 27-00-00-080-002) from the slat/flap control lever.
(6) Remove the WARNING NOTICE(S).
(7) Make sure that the work area is clean and clear of tools and other items.
Subtask 27-84-53-865-052-A (1) Remove the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT from the right slat transmission (Ref. AMM TASK 27-50-00-000-003).
(2) Remove the 98D27504030001 LOCK-TORQUE SHAFT (FLAPS AND SLATS) WITH CLAMP-PIVOT from the left slat transmission (Ref. AMM TASK 27-50-00-000-003).
(3) Pressurize the reservoirs of the Green and the Blue hydraulic systems (Ref. AMM TASK 29-14-00-614-002).
(4) Make sure that the level of 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).
(5) Remove the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION (Ref. AMM TASK 27-00-00-080-002) from the slat/flap control lever.
(6) Remove the WARNING NOTICE(S).
(7) 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 27-84-53-710-050-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/SLT/CTL AND MONG/SYS1 | 5CV | B06 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/SLT/CTL AND MONG/SYS1 | 5CV | B01 |
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/SLT/CTL/SYS2 | 7CV | R21 |
E. Test
(1) Do the operational test of the slat system (Ref. AMM TASK 27-84-00-710-001).
(2) Make sure that there are no leaks and that no fluid comes out of the seal drain line.
5. Close-up(1) Do the operational test of the slat system (Ref. AMM TASK 27-84-00-710-001).
(2) Make sure that there are no leaks and that no fluid comes out of the seal drain line.
Subtask 27-84-53-860-056-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 27-84-53-410-050-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