Installation of the Thrust Reverser Hydraulic Control Unit (HCU) [IAE]

TASK 78-31-51-400-010-A
Installation of the Thrust Reverser Hydraulic Control Unit (HCU)

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

WARNING: DO NOT GET HYDRAULIC FLUID ON YOUR SKIN, IN YOUR EYES OR IN YOUR MOUTH. HYDRAULIC FLUID IS POISONOUS AND CAN GO THROUGH YOUR SKIN AND INTO YOUR BODY. FLUSH HYDRAULIC FLUID FROM YOUR EYES, MOUTH OR SKIN WITH WATER. GET MEDICAL AID IF YOU GET HYDRAULIC FLUID IN YOUR EYES OR MOUTH.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

CAUTION: DO NOT LET HYDRAULIC FLUID FALL ON THE ENGINE. UNWANTED HYDRAULIC FLUID MUST BE REMOVED IMMEDIATELY WITH A CLEAN LINT FREE CLOTH. THE FLUID CAN CAUSE DAMAGE TO THE SURFACE PROTECTION AND TO SOME PARTS.

ZONE: 400
FIN: 4101KS1 ** ON A/C NOT FOR ALL
FIN: 4101KS2 ** ON A/C NOT FOR ALL

1. Reason for the Job
This task supplies the data to install the thrust reverser Hydraulic Control Unit (HCU).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 70 and 50 lbf.in (0.79 and 0.57 m.daN )
No specific	Torque wrench: range to between 430 and 360 lbf.in (4.86 and 4.07 m.daN )
No specific	Torque wrench: range to between 5.9 and 5.4 m.daN (43.51 and 39.82 lbf.ft )
No specific	Torque wrench: range to between 8.3 and 7.5 m.daN (61.21 and 55.31 lbf.ft )
IAE1N20049	2	PIN - LOCKOUT ACTUATOR

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V01-076)	Methyl Ethyl Ketone, Technical grade
(Material No.02ABA1)	Phosphate Ester Hydraulic Fluid-General Power - -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [1000EM1] (ENGINE-1)
437AL, 438AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
10	PACKING	AIPC 78-31-51-80-050

E. Referenced Information

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 29-10-00-863-001-A	Pressurize the Green Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-002-A	Pressurize the Yellow Hydraulic System with a Hydraulic Ground Power-Cart
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 70-23-11-911-013-A	General Torque Tightening Techniques
TASK 70-23-15-912-010-A	Connection of Electrical Connectors
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 78-30-00-440-012-A	Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance
TASK 78-31-00-710-041-A	Operational Test of the Thrust Reverser System with the CFDS
TASK 78-31-00-710-041-A-02	Operational test of the Thrust Reverser without the CFDS and Engine Running
Thrust-Reverser Hydraulic Control Unit
Thrust-Reverser Locking Actuator

3. Job Set-up
Subtask 78-31-51-860-051-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
(3) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position.

Subtask 78-31-51-010-062-A ** ON A/C NOT FOR ALL

B. Make sure that the fan cowl doors are open: (Ref. AMM TASK 71-13-00-010-010)
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR

Subtask 78-31-51-110-051-A ** ON A/C NOT FOR ALL

C. Clean component:
(1) Use a Textile-Lint free Cotton - (Material No.14SBA1) made moist with V01-076Methyl Ethyl Ketone, Technical grade to clean the HCU mounting pad on the pylon.

4. Procedure
Subtask 78-31-51-420-055-A ** ON A/C NOT FOR ALL

A. Installation of the HCU

Thrust-Reverser Hydraulic Control Unit ** ON A/C NOT FOR ALL

WARNING: YOU MUST MAKE SURE THAT THE HYDRAULIC PORT IS NOT BLOCKED. IF THE RETURN PORT IS BLOCKED THE THRUST REVERSER CAN OPERATE ACCIDENTLY AND CAUSE INJURY OR DAMAGE.

(1) Remove the caps from all the openings.
(2) Make sure that the Hydraulic Control Unit (HCU) return port is not blocked.
(3) Connect the hydraulic tubes.
(a) Lubricate the threads of the tube nut (1), (2), (6) and (7) with the Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(b) Connect the return hydraulic tube (1) to the forward end of the HCU (3) and tighten the tube nut with your hand.
(c) Connect the pressure hydraulic tube (6) and the return hydraulic tube (7) to the aft end of the HCU and tighten the tube nuts with your hand.
(d) Connect the pressure hydraulic tube (2) to the forward end of the HCU (3) and tighten the tube nut with your hand.
(4) Install the HCU (3).
(a) Attach the HCU (3) to the pylon with the three bolts (5) and the three washers (4).

NOTE: Tighten with your hand the two outer bolts (5) first, then the inner bolt (5).

(b) TORQUE the bolts (5) to between 70 and 50 lbf.in (0.79 and 0.57 m.daN )

(Ref. AMM TASK 70-23-11-911-013).
(5) Torque the tube nuts of the pressure hydraulic tubes (2) and (6), use the double torque procedure as follows:
(a) TORQUE the nut (2) and the nut (6) to between 5.9 and 5.4 m.daN (43.51 and 39.82 lbf.ft )

.
(b) Loosen the nut (2) and the nut (6) by one turn.
(c) TORQUE the nut (2) and the nut (6) to between 5.9 and 5.4 m.daN (43.51 and 39.82 lbf.ft )

.
(6) Lubricate the new AIPC 78-31-51-80-050 PACKING (10) with the Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) and install it on the return fitting (9).
(7) Install the return fitting (9) with the new packing (10) into the casing of the HCU (3).
(8) TORQUE the return fitting (9) to between 430 and 360 lbf.in (4.86 and 4.07 m.daN )

.
(9) Torque the tube nuts of the return hydraulic tubes (1) and (7), use the double torque procedure as follows:
(a) TORQUE the nut (1) and the nut (7) to between 8.3 and 7.5 m.daN (61.21 and 55.31 lbf.ft )

.
(b) Loosen the nut (1) and the nut (7) by one turn.
(c) TORQUE the nut (1) and the nut (7) to between 8.3 and 7.5 m.daN (61.21 and 55.31 lbf.ft )

.
(10) Attach the electrical connectors to the HCU (3).
(a) Connect the two electrical connectors (8) to the HCU (3) (Ref. AMM TASK 70-23-15-912-010).
(b) Tighten the two connectors with your hand plus one eighth of a turn.
(11) Apply a paint mark between the hydraulic tubes nuts and their adjacent fitting.

Subtask 78-31-51-440-054-A ** ON A/C NOT FOR ALL

B. Activate the HCU (Ref. AMM TASK 78-30-00-440-012).

Subtask 78-31-51-863-052-A ** ON A/C NOT FOR ALL

C. Pressurization of hydraulic systems

WARNING: PRESSURIZATION OF THE HYDRAULIC SYSTEM CAN RESULT IN INADVERTENT THRUST REVERSER OPERATION. REMOVE ALL PERSONNEL FROM THE AREA AROUND THE THRUST REVERSER BEFORE THE HYDRAULIC SYSTEM IS PRESSURIZED. FAILURE TO COMPLY CAN RESULT IN INJURY TO PERSONNEL.

(1) Pressurize the hydraulic reservoirs (Ref. AMM TASK 29-14-00-614-002).
(2) Pressurize the applicable hydraulic system (Ref. AMM TASK 29-10-00-863-001) or (Ref. AMM TASK 29-10-00-863-002) or (Ref. AMM TASK 29-23-00-863-001).

Subtask 78-31-51-870-050-A ** ON A/C NOT FOR ALL

D. Bleed the air from the thrust reverser hydraulic actuation system

Thrust-Reverser Locking Actuator ** ON A/C NOT FOR ALL

CAUTION: MAKE SURE THAT ALL CAUGHT AIR IS BLED FROM THE SYSTEM. IF YOU DO NOT DO THIS, CAUGHT AIR CAN CAUSE UNSATISFACTORY OPERATION OF THE TRANSLATING SLEEVES. TEN CYCLES OF TRANSLATING SLEEVE POWER EXTENSION AND RETRACTION WILL REMOVE ALL CAUGHT AIR FROM THE SYSTEM.

CAUTION: YOU MUST MOVE THE LOCK LEVERS OF THE TWO LOCKING ACTUATORS AFT TO THE UNLOCKED POSITION BEFORE YOU BLEED THE SYSTEM. IF YOU DO NOT DO THIS, UNEVEN OPERATION OF THE TRANSLATING SLEEVES CAN CAUSE DAMAGE TO THE SYSTEM.

(1) Move the lock levers (18) of the left and right locking actuators aft to the unlocked position and install the IAE1N20049 PIN - LOCKOUT ACTUATOR (19), to hold the lock levers in the unlocked position.
(2) Operate the system:

WARNING: MAKE SURE THAT THERE ARE NO PERSONS IN THE AREA AROUND THE THRUST REVERSER BEFORE YOU DO A POWER EXTENSION OR RETRACTION OF THE TRANSLATING SLEEVES. THE TRANSLATING SLEEVES EXTEND AND RETRACT IN 4.5 SECONDS OR LESS AND CAN CAUSE INJURY AND DAMAGE.

(a) Operate the system through ten cycles of translating sleeve power extension and retraction (Ref. AMM TASK 78-31-00-710-041).
(3) Remove the lockout pins:

CAUTION: THE LOCKING ACTUATOR LOCK LEVERS MUST BE IN THE FORWARD LOCKED POSITION FOR FLIGHT OPERATION.

(a) Remove the lockout pins (IAE1N20049) (19) from the lock levers (18) of the left and right locking actuators and move the lock levers forward to the locked position.
(4) Refill the hydraulic reservoir (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).

5. Close-up
Subtask 78-31-51-410-058-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(3) Remove the WARNING NOTICE(S).
(4) Remove the access platform(s).

Subtask 78-31-51-710-053-A ** ON A/C NOT FOR ALL

B. Do an operational test of the thrust reverser system (Ref. AMM TASK 78-31-00-710-041) on the FADEC channels 1A(2A) and 1B(2B).

[Rev.10 from 2021] 2026.04.01 03:27:40 UTC