Detailed Visual Inspection for Correct Installation of the Green and Yellow System Hydraulic Pipes in the MLG Bay

TASK 29-00-00-210-003-A
Detailed Visual Inspection for Correct Installation of the Green and Yellow System Hydraulic Pipes in the MLG Bay

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: OBEY THE HYDRAULIC SAFETY PROCEDURES.

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.

1. Reason for the Job
This task is necessary to look for and correct unwanted force on the hydraulic pipes that can occur during installation.
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	AR	CONTAINER - HYDRAULIC FLUID RESISTANT
No specific	AR	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)

B. 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 20-21-11-911-001-A	Tightening Torques for Standard Threaded Fasteners
TASK 20-23-11-200-001-A	Permitted Damage and Defects on Hydraulic Tubing
TASK 20-23-11-917-001-A	Tightening Practices for Hydraulic Connections
TASK 20-23-14-910-001-A	Protection of Hydraulic Lines from Vibration and Chafing
TASK 20-23-22-910-001-A	Marking of the Unions after Application of Standard or Specific Tightening Torque
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-00-00-870-001-A	Bleeding Procedure of the Green Hydraulic System Upstream of the Engine Pump
TASK 29-00-00-910-002-A	Safety Procedures of the Hydraulic System
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 29-14-00-614-001-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 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
Green Hydraulic System - Main Landing Gear (MLG) Bay
Yellow Hydraulic System - Main Landing Gear (MLG) Bay

3. Job Set-up
Subtask 29-00-00-941-053-A

A. Safety Precautions
(1) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(2) Put a WARNING NOTICE(S) in position to tell persons not to pressurize the Green and Yellow hydraulic systems.
(3) Put a WARNING NOTICE(S) in position to tell persons not to operate the MLG doors.
(4) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.

Subtask 29-00-00-010-066-A

B. Get Access
(1) Open the MLG doors (Ref. AMM TASK 32-12-00-010-001).
(2) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position below the MLG bay.

Subtask 29-00-00-860-092-A

C. Aircraft Maintenance Configuration
(1) Depressurize the Green and Yellow hydraulic systems (Ref. AMM TASK 29-00-00-864-001).

4. Procedure
Subtask 29-00-00-210-056-A

A. Detailed Visual Inspection for Correct Installation of the Green and Yellow System Hydraulic Pipes in the MLG Bay
(1) Examine the hydraulic pipes and make sure that they are in the correct condition (Ref. AMM TASK 20-23-11-200-001).
(2) Examine these items for damage or wear:

The attachment clamps
The attachment brackets
The attachment nuts, bolts and washers.

(3) If one or more of the attachment items are damaged or missing, replace them.

NOTE: The steps that follow are to make sure that the clamp/bracket assemblies only support the weight of the hydraulic pipes. An incorrect installation will put unwanted force on the hydraulic pipes.

(4) For the applicable pipe(s), remove the clamp/bracket assemblies one at a time as follows:
(a) Remove the attachment nuts, bolts and washers of the clamp.
(b) Remove the top clamp block.
(c) Make sure that the pipe is held on the bottom clamp block without force.
(d) If necessary, loosen the attachment nuts, bolts and washers of the structure bracket. Align the bottom clamp bolt holes with the bracket bolt holes.
(e) Install the top clamp block and make sure that the bolt holes of the clamp blocks and the bracket all align correctly.
(f) Install and tighten the attachment nuts, bolts and washers. Do not over-tighten.
(g) Make sure that the pipe is held correctly and without force.
1 If there is space between the clamp and the pipe, safety the pipe against vibration (Ref. AMM TASK 20-23-14-910-001).
(h) Do steps (4)(a) to (4)(g) for each clamp/bracket assembly of the applicable pipe(s).
(5) If correct alignment of the applicable pipe is not possible, then you must do the steps that follow:
(a) Depressurize the Green and Yellow hydraulic system reservoirs (Ref. AMM TASK 29-14-00-614-001).
(b) Put a CONTAINER - HYDRAULIC FLUID RESISTANT below the applicable pipe union.
(c) Disconnect the union(s) of the applicable pipe(s) as necessary.
(d) Do again the steps (4)(a) to (4)(g) for each clamp/bracket assembly of the applicable pipe(s).
(e) Connect the union(s) of the applicable pipe(s) and tighten with your hand.
(f) TORQUE the union(s) of the hydraulic pipe(s) using double tightening procedure (Ref. AMM TASK 20-23-11-917-001).

NOTE: Do not twist the pipe(s) when you tighten the union(s). The pipe(s) must not be installed with force.

(g) Mark the pipe(s) and union(s) after TORQUE tightening (Ref. AMM TASK 20-23-22-910-001).
(6) TORQUE the nuts and/or bolts of the brackets and clamps (Ref. AMM TASK 20-21-11-911-001).
(7) Make sure that the hydraulic pipes have sufficient clearance (Ref. AMM TASK 20-23-14-910-001).

Subtask 29-00-00-790-052-A

B. Leak Test

NOTE: Only do this leak test if you have disconnected the applicable hydraulic pipe(s) for correct alignment.

(1) Make sure that the levels of fluid in the reservoirs of the Green and Yellow systems are correct. Add fluid as necessary (Ref. AMM TASK 12-12-29-611-001) or (Ref. AMM TASK 12-12-29-611-002).
(2) Pressurize the Green and Yellow hydraulic reservoirs (Ref. AMM TASK 29-14-00-614-002).
(3) Pressurize the Green and Yellow hydraulic systems (Ref. AMM TASK 29-10-00-863-001) and (Ref. AMM TASK 29-10-00-863-002).
(4) Bleed the air in the Green and Yellow hydraulic systems (Ref. AMM TASK 29-00-00-870-001).
(5) Examine the applicable pipe union(s) for leaks.
(6) Remove the container.

5. Close-up
Subtask 29-00-00-410-069-A

A. Close Access
(1) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).
(4) Close the MLG doors (Ref. AMM TASK 32-12-00-410-001).

[Rev.10 from 2021] 2026.04.01 00:13:36 UTC