Installation of the Manual Drive Unit (MDU) [CFML]

TASK 78-31-45-400-801-A
Installation of the Manual Drive Unit (MDU)

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.

ZONE: 400
FIN: 3041KM
FIN: 3042KM

1. Reason for the Job

NOTE: The left-hand lower actuator is also known as the synchronized non-locking actuator (3041KM).
The right-hand lower actuator is also known as the synchronized manual locking actuator (3042KM).

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	WARNING NOTICE(S)
No specific	1	WRENCH - FLAT
No specific	1	WRENCH - TORQUE
No specific	Torque wrench: range to between 398 and 363 lbf.in (4.50 and 4.10 m.daN )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 73-29-00-740-804-A	Thrust Reverser Cycling Test (Menu Mode)
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-30-00-440-807-A	Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU)
Manual Drive Unit (MDU)
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
TASK 29-10-00-863-001-A	Pressurize the Green 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)
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
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)

3. Job Set-up
Subtask 78-31-45-941-051-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Make sure that the WARNING NOTICE(S) are in position to tell persons not to operate:

The ENG/MODE selector switch
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Make sure that the WARNING NOTICE(S) is in position to tell persons not to energize FADEC 1(2).

Subtask 78-31-45-010-051-A

B. Get Access
(1) Make sure that the fan cowl doors are open (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.

Subtask 78-31-45-040-051-A

C. Deactivation of the Thrust Reverser System for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Make sure that you did the deactivation of the thrust reverser system for nacelle maintenance (Ref. AMM TASK 78-30-00-040-807).

4. Procedure
Subtask 78-31-45-420-050-A

A. Installation of the Manual Drive Unit (MDU)

Manual Drive Unit (MDU)

WARNING: USE PERSONAL PROTECTIVE EQUIPMENT WHEN YOU DO WORK ON THE HYDRAULIC THRUST REVERSER ACTUATION SYSTEM (TRAS). HYDRAULIC FLUID CAN CAUSE INJURY TO PERSONS AND DAMAGE TO ENGINE PARTS.

CAUTION: DO NOT LET HYDRAULIC FLUID FALL ON THE ENGINE OR THE THRUST REVERSER. 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.

(1) Remove all COVER - PROTECTION and CAP - PROTECTION from the openings, tubes, hoses and connectors.
(2) Manually install the MDU (3) in the right lower actuator (4).
(3) Torque the MDU.

CAUTION: HOLD THE ACTUATOR FITTING WHILE YOU TURN THE MDU. IF THE ACTUATOR FITTING BECOMES LOOSE, THE ACTUATOR WILL BE UNSERVICEABLE.

(a) Use a WRENCH - TORQUE to hold the fitting on the right lower actuator (4).
(b) TORQUE the MDU (3) with a second WRENCH - FLAT to between 398 and 363 lbf.in (4.50 and 4.10 m.daN )

.
(4) Manually install the MDU (2) in the left lower actuator (1).
(5) Torque the MDU.

CAUTION: HOLD THE ACTUATOR FITTING WHILE YOU TURN THE MDU. IF THE ACTUATOR FITTING BECOMES LOOSE, THE ACTUATOR WILL BE UNSERVICEABLE.

(a) Use a WRENCH - TORQUE to hold the fitting on the left lower actuator (1).
(b) TORQUE the MDU (2) with a second WRENCH - FLAT to between 398 and 363 lbf.in (4.50 and 4.10 m.daN )

5. Close-up
Subtask 78-31-45-863-050-A

A. Pressurization of the Aircraft Hydraulic Systems
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
(a) Pressurize the reservoir of the Green hydraulic system (Ref. AMM TASK 29-14-00-614-002).
(b) Pressurize the Green hydraulic system (Ref. AMM TASK 29-10-00-863-001).
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
(a) Pressurize the reservoir of the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-002).
(b) Pressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-002).

Subtask 78-31-45-870-050-A

B. Bleed the thrust reverser hydraulic system
(1) Do the thrust reverser cycling test ten times (Ref. AMM TASK 73-29-00-740-804).
(2) Do a visual inspection of the MDUs and lower actuators to make sure that there is no leakage.

Subtask 78-31-45-440-050-A

C. Do the reactivation of the thrust reverser system after nacelle maintenance (Ref. AMM TASK 78-30-00-440-807).

Subtask 78-31-45-410-050-A

D. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 03:35:20 UTC