Functional Check of MLG Shock Absorber Fluid Level

TASK 12-12-32-611-004-A
Functional Check of MLG Shock Absorber Fluid Level

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: 731
ZONE: 741

1. Reason for the Job
Refer to the MPD TASK: 321113-03
FUNCTIONAL CHECK OF MLG SHOCK ABSORBER FLUID LEVEL

NOTE: If you find a deflated MLG shock absorber after the aircraft landing, there can be structural or landing-gear component damage. You must contact AIRBUS for instructions with the results of AMM TASK 32-11-00-200-001-A.

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

REFERENCE	QTY	DESIGNATION
No specific	1	CHARGING EQUIPMENT - FLUID, STANDARD
No specific	AR	SAFETY BARRIER(S)
No specific	1	THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F)
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.79 and 0.57 m.daN (69.91 and 50.44 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
731	L.H MAIN GEAR
741	R.H MAIN GEAR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 12-12-32-611-008-A	Hydraulic Replenishment of the MLG Two-Stage Shock Absorber
TASK 12-14-32-614-003-A	Functional Check of MLG Shock Absorber Charge Pressure
TASK 32-00-00-481-001-A	Installation of the Safety Devices on the Landing Gears
MLG Two Stage Shock Absorber - Dimension H
MLG Two Stage Shock Absorber Charging Valves - Detail and Location
MLG Two Stage Shock Absorber - Typical Filling System
MLG Two-Stage Shock Absorber - Pressure/Extension Graph (Metric Units) ** ON A/C NOT FOR ALL
MLG Two-Stage Shock Absorber - Pressure/Extension Graph (Metric Units) ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 12-12-32-941-063-A

A. Safety Precautions
(1) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(2) Make sure that the ground safety locks are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(3) On the panel 400VU:

make sure that the landing-gear control-lever 6GA is in the DOWN position
put a WARNING NOTICE(S) in position to tell persons not to operate the landing gear.

(4) Put a WARNING NOTICE(S) in position to tell persons not to operate the landing gear doors.

4. Procedure
Subtask 12-12-32-220-051-A

WARNING: MAKE SURE THAT THE STANDARD CHARGING EQUIPMENT IS SAFE TO USE ABOVE 140 BAR (2030.5 PSI). THIS WILL PREVENT INJURY AND DAMAGE.

WARNING: MAKE SURE THAT THE AREA AROUND THE AIRCRAFT IS CLEAR OF PERSONS AND EQUIPMENT. WHEN YOU PRESSURIZE/DEPRESSURIZE THE SHOCK ABSORBER, WITH THE AIRCRAFT WEIGHT ON THE GROUND, THE AIRCRAFT WILL MOVE.

CAUTION: ALWAYS ADD NITROGEN SLOWLY WHEN YOU PRESSURIZE THE SHOCK ABSORBER. IF YOU ADD THE NITROGEN TOO QUICKLY, THE TEMPERATURE WILL INCREASE AND HAVE AN EFFECT ON THE SHOCK ABSORBER PRESSURE.

CAUTION: MAKE SURE THAT YOU USE A GAGE WITH THE SPECIFIED PRESSURE RANGE. THIS IS NECESSARY TO GET AN ACCURATE PRESSURE MEASUREMENT.

A. Functional Check of the MLG Shock-Absorber Fluid Level

NOTE: To do this procedure it is necessary to have the CHARGING EQUIPMENT - FLUID, STANDARD and the THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F). The charging equipment must be safe to use at more than 140 bar (2030.5 psi).

(1) Do the nitrogen filling of the MLG two-stage shock absorber (Ref. AMM TASK 12-14-32-614-003).

NOTE: If the aircraft is on jacks, it is necessary:

That you wait a minimum of one hour after you remove the jacks before you do the procedure that follows. This will let you get a stable temperature and an accurate value of the shock absorber extension and pressure.

(2) Measure and record dimension H.

MLG Two Stage Shock Absorber - Dimension H

(3) Install the standard charging equipment on the top charging valve (1):

MLG Two Stage Shock Absorber Charging Valves - Detail and Location

MLG Two Stage Shock Absorber - Typical Filling System

NOTE: If the equipment manufacturer's assembly/operating instructions are different to the data given, use the equipment manufacturers's instructions.

(a) Remove the blanking cap (2) from the top charging valve (1).
(b) Make sure that the control valves (13) and (15) are closed.
(c) Connect the filling hose (11) to the three-way valve (12).
(d) Connect the filling hose (11) to the top charging valve (1).
(e) Install the pressure gage 140 bar (2030.5 psi) (10) on the three-way valve (12).
(4) Slowly open the top charging valve (1).
(5) At the top charging valve (1), read and record the pressure shown on the pressure gage (10).
(6) Close the top charging valve (1).
(7) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure the temperature of the MLG adjacent to the top charging valve (1).

NOTE: It is necessary to know the accurate temperature measured to follow the procedure.

(8) Find dimension H for the pressure at the top charging valve (1) for the measured temperature given in diagram 1.

MLG Two-Stage Shock Absorber - Pressure/Extension Graph (Metric Units) ** ON A/C NOT FOR ALL

(9) Compare dimension H given in diagram 1 to the measured dimension H and do one of the steps that follow:
(a) If the measured dimension H is between +/- 15 mm (0.59 in.) of the dimension given in diagram 1, do step (10). This result shows that the fluid level is correct.
(b) If the measured dimension H is not between +/- 15 mm (0.59 in.) but is between +/- 30 mm (1.18 in.) of the dimension given in diagram 1, do step (11).
(c) If the measured dimension H is more than +/- 30 mm (1.18 in.) of the dimension given in diagram 1, do step (14).
(10) If the measured dimension H is between +/- 15 mm (0.59 in.) of the dimension H given in diagram 1, do the steps that follow:

NOTE: The measured dimension H can be as low as 33 mm (1.30 in.) at very low ambient temperatures. This is usual for a shock absorber in good condition and no maintenance is necessary (if the measured dimension H is between +/- 15 mm (0.59 in.) of the correct value).

(a) Make sure that the control valve (15) is closed.
(b) Open the control valve (13) to release all pressure from the filling hose (11).
(c) Close the control valve (13).
(d) Remove the pressure gage (10) from the three-way valve (12).
(e) Disconnect the filling hose (11) from the top charging valve (1) and the three-way valve (12).
(f) TORQUE the top charging valve (1) to between 0.79 and 0.57 m.daN (69.91 and 50.44 lbf.in )

.
(g) Install the blanking cap (2) on the top charging valve (1).
(h) Do the close-up procedure in Para 5.A.
(11) If the measured dimension H is not between +/- 15 mm (0.59 in.) but is between +/- 30 mm (1.18 in.) of the dimension H given in diagram 1:

Do steps, (12) or (13).

(12) Do the hydraulic replenishment of the MLG two-stage shock absorber (Ref. AMM TASK 12-12-32-611-008).
(13) If the measured dimension H is between +/- 30 mm (1.18 in.) of the dimension H given in diagram 1:
(a) Record in the aircraft log to do the hydraulic replenishment of the two-stage shock absorber (Ref. AMM TASK 12-12-32-611-008) before 50 flight cycles
(b) Do the steps that follow:
1 Make sure that the control valve (15) is closed on the three-way valve (12).
2 Open the control valve (13) on the three-way valve (12), to release all pressure from the filling hose (11).
3 Close the control valve (13) on the three-way valve (12).
4 Remove the pressure gage (10) from the three-way valve (12).
5 Disconnect the filling hose (11) from the top charging valve (1) and the three-way valve (12).
6 TORQUE the top charging valve (1) to between 0.79 and 0.57 m.daN (69.91 and 50.44 lbf.in )

.
7 Install the blanking cap (2) on the top charging valve (1).
8 Do the close-up procedure in Para 5.A.
(14) If the measured dimension H is more than +/- 30 mm (1.18 in.) of the dimension H given in diagram 1:

Do the hydraulic replenishment of the MLG two-stage shock absorber (Ref. AMM TASK 12-12-32-611-008).

5. Close-up
Subtask 12-12-32-942-076-A

A. Remove the Equipment
(1) Remove the SAFETY BARRIER(S).
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 06:10:15 UTC