Flushing of the Yellow Hydraulic System of the Flap Power Control-Unit (PCU)

TASK 12-36-29-170-008-A
Flushing of the Yellow Hydraulic System of the Flap Power Control-Unit (PCU)

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: DO NOT GET THE FLUID ON YOUR SKIN OR IN YOUR EYES. IF YOU DO:

FLUSH IT AWAY WITH CLEAN WATER
GET MEDICAL AID.

1. Reason for the Job
To flush the Yellow hydraulic system after a failure in that part of the flap PCU 6201CM.
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	1	CONTAINER 5 L (1.32 USGAL)
No specific	1	LOCALLY MANUFACTURED - ADAPTER
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY BARRIER(S)
No specific	1	WARNING NOTICE(S)
ALT29000001	1	HYD GRND PWR UNIT3000

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
196BB, 198CB

C. Referenced Information

REFERENCE	DESIGNATION
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 29-10-00-863-002-A	Pressurize the Yellow Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-864-002-A	Depressurize the Yellow Hydraulic System
TASK 29-13-44-610-001-A	Servicing of the LP-Filter
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
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
Yellow Hydraulic System of the Flap PCU 6201CM - Flushing Schematic

3. Job Set-up
Subtask 12-36-29-860-071-A

A. Aircraft Maintenance Configuration
(1) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(2) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(3) Depressurize the reservoir of the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-001).
(4) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).

Subtask 12-36-29-010-091-A

B. Get Access
(1) Open the right MLG door (Ref. AMM TASK 32-12-00-010-001).
(2) Open the access door 198CB.
(3) Open the access panel 196BB.

Subtask 12-36-29-860-072-A

C. Preparation for the Flushing Procedure
(1) Put the WARNING NOTICE(S) in position.
(2) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(3) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position at the Zone 148.
(4) Put a CONTAINER 5 L (1.32 USGAL) in position to collect the hydraulic fluid below:

the flap PCU 6201CM,
the LP manifold 3003GM.

(5) Disconnect the case drain line from the motor in the Yellow hydraulic system of the flap PCU 6201CM.
(6) Disconnect the pressure line from the valve block 24CV in the Yellow hydraulic system of the flap PCU 6201CM.
(7) Disconnect the case drain line from the LP manifold 3003GM.
(8) Put the ALT29000001 HYD GRND PWR UNIT3000 in position as necessary.
(9) Connect the pressure line to the case drain line with a union at the flap PCU 6201CM.

CAUTION: MAKE SURE THAT THE FLOW RATE AND THE SUPPLY PRESSURE ON THE GROUND HYDRAULIC CART ARE SET TO A MINIMUM.

(10) Connect the pressure hose of the ALT29000001 HYD GRND PWR UNIT3000 to the delivery connector 3008GM with an LOCALLY MANUFACTURED - ADAPTER.
(11) Connect the return hose of the ALT29000001 HYD GRND PWR UNIT3000 to the case drain line at the LP manifold 3003GM with an LOCALLY MANUFACTURED - ADAPTER.
(12) Put the PLUG-BLANKING in each disconnected line end.

4. Procedure
Subtask 12-36-29-170-057-A

A. Flush the Yellow hydraulic system.
(1) Operate the hydraulic power cart for 20 s at 20 bar (290.0754 psi).
(2) Stop the hydraulic power cart.

Subtask 12-36-29-960-057-A

B. Replace the LP filter element (Ref. AMM TASK 29-13-44-610-001).

5. Close-up
Subtask 12-36-29-860-073-A

A. Put the system back to the serviceable condition.
(1) Disconnect the pressure hose of the hydraulic power cart and the adaptor from the delivery connector 3008GM.
(2) Disconnect the return hose of the hydraulic power cart and the adaptor from the case drain line.
(3) Disconnect and remove the union from the case drain line and the pressure line at the flap PCU 6201CM.
(4) Remove the hydraulic power cart.
(5) Remove the blanking plugs.
(6) Connect the case drain line to the LP manifold 3003GM.
(7) Connect the case drain line to the motor in the Yellow hydraulic system of the flap PCU 6201CM.
(8) Connect the pressure line to the valve block 24CV in the Yellow hydraulic system of the flap PCU 6201CM.

Subtask 12-36-29-790-057-A

B. Leak Test of the Components which were Disconnected
(1) Pressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-002).
(2) Make sure that there is no hydraulic fluid leakage.
(3) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).

Subtask 12-36-29-942-096-A

C. Put the aircraft back to its initial configuration.
(1) Remove the containers.
(2) Remove the safety barriers.
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).

Subtask 12-36-29-410-078-A

D. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the right MLG door (Ref. AMM TASK 32-12-00-410-001).
(3) Close the access door 198CB.
(4) Close the access panel 196BB.
(5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 06:10:39 UTC