Installation of the MLG Door Actuating-Cylinder

TASK 32-31-35-400-001-A
Installation of the MLG Door Actuating-Cylinder

WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.

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.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES.

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

ZONE: 734
ZONE: 744
FIN: 2522GM
FIN: 2523GM

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 5.50 and 2.75 m.daN (40.56 and 20.28 lbf.ft )
No specific	Torque wrench: range to between 3.2 and 2.9 m.daN (23.60 and 21.39 lbf.ft )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03HBD9)	Synthetic Ester base Grease-General Purpose Low Temp -
(Material No.04SAB2)	Varnish Polyurethane-- Marking Structure
(Material No.06AAB1)	Polysulfide Sealant-General Purpose Fillet -
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.08BBH1)	Non Aqueous Cleaner-- Acetone -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
734	MAIN DOOR
744	MAIN DOOR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
11	COTTER PIN	AIPC 32-31-03-60-030
12	COTTER PIN	AIPC 32-31-03-60-030
8	COTTER PIN	AIPC 32-31-03-60-030
9	COTTER PIN	AIPC 32-31-03-60-030
5	SHIM WASHER	AIPC 32-31-03-60-080
11	COTTER PIN	AIPC 32-31-83-60-030
12	COTTER PIN	AIPC 32-31-83-60-030
8	COTTER PIN	AIPC 32-31-83-60-030
9	COTTER PIN	AIPC 32-31-83-60-030

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 12-22-32-640-001-A	Lubrication of Main Landing Gear and Doors
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 29-00-00-910-002-A	Safety Procedures of the Hydraulic System
TASK 29-10-00-864-001-A	Depressurize the Green Hydraulic System
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 29-23-00-860-001-A	Disconnection of the Isolation Coupling of the Power Transfer Unit (PTU)
TASK 29-23-00-860-002-A	Connection of the Isolation Coupling of the Power Transfer Unit (PTU)
TASK 32-00-00-860-001-A	Flight Configuration Precautions with Electrical Power
TASK 32-00-00-860-001-A-01	Flight Configuration Precautions without Electrical Power
TASK 32-00-00-860-002-A	Ground Configuration after Flight Configuration with Electrical Power
TASK 32-00-00-860-002-A-01	Ground Configuration after Flight Configuration without Electrical Power
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
TASK 32-31-00-720-803-A	Functional Check of the MLG Door Actuating Cylinder
TASK 51-75-13-916-002-A	Repair to a layer of Corrosion Preventive Compound
TASK 32-12-11-400-001-A	Installation of the Door Assembly - Main (for corrective action)
MLG Door Actuating-Cylinder ** ON A/C NOT FOR ALL
MLG Door Actuating-Cylinder ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 32-31-35-860-051-A

A. Aircraft Maintenance Configuration
(1) Make sure that the PTU isolation coupling is disconnected (Ref. AMM TASK 29-23-00-860-001).
(2) Make sure that the electrical circuits are de-energized (Ref. AMM TASK 24-41-00-862-002) or the flight configuration precautions were obeyed (Ref. AMM TASK 32-00-00-860-001).
(3) Make sure that the Green hydraulic system is depressurized (Ref. AMM TASK 29-10-00-864-001).
(4) Make sure that the reservoir of the Green hydraulic system is depressurized (Ref. AMM TASK 29-14-00-614-001).

Subtask 32-31-35-865-054-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	L/G/LGCIU/SYS1/NORM	1GA	C09
** ON A/C NOT FOR ALL
49VU	HYDRAULIC/G HYD/PUMP ENG1/CTL	1701GK	H12
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/CTL	1701GK	R35
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/MONG	1702GK	R34
** ON A/C ALL
121VU	HYDRAULIC/LGCIU/SYS2	2GA	Q35
121VU	HYDRAULIC/LGCIU/SYS1/GRND SPLY	52GA	Q34
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/MONG	1702GK	R33

Subtask 32-31-35-941-051-A

C. Safety Precautions
(1) Make sure that the WARNING NOTICE(S) are in position to tell persons not to pressurize the Green hydraulic system:

On the panel 40VU in the cockpit.
On the ground service panel of the Green hydraulic system.

4. Procedure
Subtask 32-31-35-420-051-A ** ON A/C NOT FOR ALL

WARNING: USE PROTECTIVE GOGGLES WHEN YOU REMOVE OR INSTALL A COTTER PIN. EACH TIME YOU REMOVE A COTTER PIN DURING THE TASK, DISCARD IT IMMEDIATELY. A LOOSE COTTER PIN CAN CUT YOU OR MAKE YOU BLIND.

A. Installation of the Actuating-Cylinder

MLG Door Actuating-Cylinder ** ON A/C NOT FOR ALL

(1) Clean the component with Non Aqueous Cleaner-- Acetone - (Material No.08BBH1) or Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.
(4) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(5) Put the actuating-cylinder (4) in position on the aircraft. Make sure that the greasers (2) are in the correct position for easy lubrication.
(6) Installation of the bolts (1) and (10):

CAUTION: MAKE SURE THAT YOU INSTALL THE ACTUATOR TOP AND BOTTOM BOLTS WITH THE BOLT HEAD ON THE SAME SIDE AS THE FLANGED BUSHING. INCORRECT INSTALLATION OF THE BOLT CAN CAUSE THE BOLT TO MOVE THROUGH THE BUSHINGS. THIS CAN CAUSE A FAILURE OF THE MAIN LANDING GEAR DOOR.

(a) Install the bolt (1) and the spacer (6) in the upper support bracket. Make sure that you install the head of the bolt (1) on the same side as the flanged bush.
(b) Install the bolt (10) and the spacer (14) in the lower support bracket. Make sure that you install the head of the bolt (10) on the same side as the flanged bush.
(7) Install the washers (7) and (13) on the bolts (1) and (10) with the nuts (8) and (12).

CAUTION: DO NOT APPLY A TORQUE OF MORE THAN 5.5 M.DAN (40.56 LBF.FT) WHEN YOU INSTALL THE ACTUATOR. TOO MUCH TORQUE CAN CAUSE CRACKS TO THE ACTUATOR FITTING LUGS.

(8) TORQUE the nuts (8) and (12) to between 5.50 and 2.75 m.daN (40.56 and 20.28 lbf.ft )

as follows:
(a) Apply a minimum torque value of 2.75 m.daN (20.28 lbf.ft) to the nuts (8) and (12).
(b) Increase the torque until the first cotter pin hole is aligned with a slot of the nuts (8) and (12).
(c) Do not torque the nuts (8) and (12) to more than the maximum torque value of 5.50 m.daN (40.56 lbf.ft).
(9) Make sure that clearance A is not less than 0.1 mm (0.004 in.).
(10) If clearance A is less than 0.1 mm (0.004 in.):

Install the AIPC 32-31-03-60-080 SHIM WASHER (5) between the bearing and the spacer (6) to get the correct clearance A.

(11) Safety the nut (8) with the new AIPC 32-31-03-60-030 COTTER PIN (9) or the new AIPC 32-31-83-60-030 COTTER PIN (9).
(12) Safety the nut (12) with the new AIPC 32-31-03-60-030 COTTER PIN (11) or the new AIPC 32-31-83-60-030 COTTER PIN (11).
(13) Remove the PLUG-BLANKING from each disconnected line end.
(14) Connect the connectors (3) to the actuating-cylinder (4).
(15) TORQUE the connectors (3) to between 3.2 and 2.9 m.daN (23.60 and 21.39 lbf.ft )

.
(16) Put a mark on the connectors (3) and the connectors of the actuating-cylinder (4) with Varnish Polyurethane-- Marking Structure (Material No.04SAB2) .
(17) Lubricate the bearings at each end of the actuating-cylinder (4) through the lubrication fittings (2) (Ref. AMM TASK 12-22-32-640-001).

NOTE: The MLG door actuator-bearing housing can show signs of circular movement. This is permitted, but if there is lateral movement of the MLG door actuator-bearing housing, you must replace the bearing housing.

(18) Apply Polysulfide Sealant-General Purpose Fillet - (Material No.06AAB1) to the heads of the bolts (1) and (10) and the nuts (8) and (12).

Subtask 32-31-35-420-051-C ** ON A/C NOT FOR ALL

WARNING: USE PROTECTIVE GOGGLES WHEN YOU REMOVE OR INSTALL A COTTER PIN. EACH TIME YOU REMOVE A COTTER PIN DURING THE TASK, DISCARD IT IMMEDIATELY. A LOOSE COTTER PIN CAN CUT YOU OR MAKE YOU BLIND.

A. Installation of the Actuating Cylinder

MLG Door Actuating-Cylinder

MLG Door Actuating-Cylinder ** ON A/C NOT FOR ALL

(1) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(2) Clean the component with Non Aqueous Cleaner-- Acetone - (Material No.08BBH1) or Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(3) Do an inspection of the component interfaces and the adjacent area.
(4) Make sure that the parts retained from the removed component are clean and in the correct condition.
(5) Put the actuating-cylinder (4) in position on the aircraft. Make sure that the greasers (2) are in the correct position for easy lubrication.
(6) Apply Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the bolts (1) and (9).
(7) Installation of the bolts (1) and (9):

(a) Install the bolt (1) and the spacer (5) in the upper support bracket. Make sure that you install the head of the bolt (1) on the same side as the flanged bush.
(b) Install the bolt (9) and the spacer (10) in the lower support bracket. Make sure that you install the head of the bolt (9) on the same side as the flanged bush.
(8) Install the washers (6) and (11) on the bolts (1) and (9) with the nuts (7) and (13).

CAUTION: DO NOT APPLY A TORQUE OF MORE THAN 5.5 M.DAN (40.56 LBF.FT) WHEN YOU INSTALL THE ACTUATOR. TOO MUCH TORQUE CAN CAUSE CRACKS TO THE ACTUATOR FITTING LUGS.

(9) TORQUE the nuts (7) and (13) to between 5.50 and 2.75 m.daN (40.56 and 20.28 lbf.ft )

as follows:
(a) Apply a minimum torque value of 2.75 m.daN (20.28 lbf.ft) to the nuts (7) and (13).
(b) Increase the torque until the first cotter pin hole is aligned with a slot of the nuts (7) and (13).
(c) Do not torque the nuts (7) and (13) to more than the maximum torque value of 5.50 m.daN (40.56 lbf.ft).
(10) Safety the nut (7) with the new AIPC 32-31-03-60-030 COTTER PIN (8) or the new AIPC 32-31-83-60-030 COTTER PIN (8).
(11) Safety the nut (13) with the new AIPC 32-31-03-60-030 COTTER PIN (12) or the new AIPC 32-31-83-60-030 COTTER PIN (12).
(12) Remove the PLUG-BLANKING from each disconnected line end.
(13) Connect the connectors (3) to the actuating-cylinder (4).
(14) TORQUE the connectors (3) to between 3.2 and 2.9 m.daN (23.60 and 21.39 lbf.ft )

.
(15) Make a mark on the connectors (3) and the connectors of the actuating-cylinder (4) with Varnish Polyurethane-- Marking Structure (Material No.04SAB2) .
(16) Lubricate the bearings at each end of the actuating-cylinder (4) through the greasers (2) (Ref. AMM TASK 12-22-32-640-001).

(17) Apply Polysulfide Sealant-General Purpose Fillet - (Material No.06AAB1) to the heads of the bolts (1) and (9) and the nuts (7) and (13).

Subtask 32-31-35-865-055-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	L/G/LGCIU/SYS1/NORM	1GA	C09
** ON A/C NOT FOR ALL
49VU	HYDRAULIC/G HYD/PUMP ENG1/CTL	1701GK	H12
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/CTL	1701GK	R35
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/MONG	1702GK	R34
** ON A/C ALL
121VU	HYDRAULIC/LGCIU/SYS2	2GA	Q35
121VU	HYDRAULIC/LGCIU/SYS1/GRND SPLY	52GA	Q34
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/MONG	1702GK	R33

Subtask 32-31-35-860-052-A

C. Preparation for Test
(1) Connect the PTU isolation coupling (Ref. AMM TASK 29-23-00-860-002).
(2) If the flight configuration precautions were obeyed, put the aircraft back to the serviceable condition (Ref. AMM TASK 32-00-00-860-002).
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Remove the container below the MLG door actuating cylinder 2523GM (2522GM).
(5) Make sure that the travel ranges of the MLG doors are clear.
(6) Remove the WARNING NOTICE(S).
(7) Remove the access platform(s).

Subtask 32-31-35-710-051-A

D. Functional Test
(1) Do 5 full DOOR CLOSE/DOOR OPEN cycles (Ref. AMM TASK 32-12-00-010-001) (Ref. AMM TASK 32-12-00-410-001).
(2) Make sure that the MLG door(s) is(are) flush with the adjacent airframe structure (Ref. AMM TASK 32-12-11-400-001).
(3) Make sure that there are no anomalies during these operations.
(4) Open the applicable MLG door(s) (Ref. AMM TASK 32-12-00-010-001).
(5) Put the ACCESS PLATFORM 1M(3 FT) in position below the MLG door actuating cylinder 2523GM (2522GM).
(6) Make sure that there is no hydraulic fluid leakage from the actuating cylinder 2523GM (2522GM).
(7) If necessary fill the reservoir of the Green hydraulic system to the correct level (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
(8) Do the functional check of the MLG door actuating-cylinder (Ref. AMM TASK 32-31-00-720-803).

5. Close-up
Subtask 32-31-35-410-051-A

A. Close Access
(1) Apply corrosion protection to the connectors (3) and the adjacent areas (Ref. AMM TASK 51-75-13-916-002).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the applicable MLG door (Ref. AMM TASK 32-12-00-410-001).
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.01 12:30:18 UTC