Reactivation of the FWD ACT's Isolation Valve

TASK 28-28-00-440-005-A
Reactivation of the FWD ACT's Isolation Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

FIN: 236QM ** ON A/C NOT FOR ALL

1. Reason for the Job
MMEL 28-28-16A
FORWARD ACT ISOLATION VALVE
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	BRIDGE-WIRE
No specific	AR	TIE WRAP(S)
No specific	AR	WARNING NOTICE(S)
T720456	AR	TOOL - VALVE LOCKING

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
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 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-28-61-000-001-A	Removal of the ACT Isolation Valve
TASK 28-28-61-400-001-A	Installation of the ACT Isolation Valve
TASK 28-28-71-400-001-A	Installation of the ACT Isolation-Valve Actuator
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
ACT-FWD Isolation-Valve Actuator

3. Job Set-up
Subtask 28-28-00-860-116-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) When you do maintenance work on the fuel system you must obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(3) On the APU section of overhead panel 25VU make sure that the APU/MASTER SW pushbutton switch is released (the ON legend is off).
(4) On the FUEL section of panel 40VU make sure that all tank pump pushbutton switches are released (the OFF legends are on).
(5) Put a WARNING NOTICE(S) in position:

On the APU section of overhead panel 25VU to tell persons not to operate the APU/MASTER SW pushbutton switch
On the FUEL section of panel 40VU to tell persons not to operate the fuel system
On the ENG/APU FIRE panel located on the overhead panel 20VU, to tell persons not to operate the fire extinguishing system
On the Additional Center Tank (ACT) control section of panel 28VU to tell persons not to operate the fuel system.

(6) Put a WARNING NOTICE(S) in position on the MLG doors to tell persons not to operate the MLG doors.

Subtask 28-28-00-010-062-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the left MLG door (Ref. AMM TASK 32-12-00-010-001).
(2) Put an ACCESS PLATFORM 2M (6 FT) in position in the left MLG bay.

4. Procedure
Subtask 28-28-00-440-054-B ** ON A/C NOT FOR ALL

A. Reactivation of the ACT Forward Isolation-Valve

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(1) Cut and discard the lock wire from the screw (5).
(2) Loosen the screw (5) and remove the clamp (6) from the shaft of the ACT forward isolation-valve (1).
(3) Remove the T720456 TOOL - VALVE LOCKING from the flange of the ACT forward isolation-valve (1).
(4) Do an inspection of the component interfaces and the adjacent area.

CAUTION: MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT.

(5) Remove and discard the TIE WRAP(S) from the electrical connectors (3) and (4) and from the adjacent electrical harness.
(6) Remove the CAP-BLANKING from each electrical connector and receptacle.
(7) Remove the BRIDGE-WIRE (shunt) from the electrical connector (3).
(8) If the ACT forward isolation-valve (1) has a failure in the closed position, replace the unserviceable ACT forward isolation-valve (1) (Ref. AMM TASK 28-28-61-000-001) (Ref. AMM TASK 28-28-61-400-001).
(9) If the actuator (2) of the ACT forward isolation-valve (1) is unserviceable, install a new actuator (2) (Ref. AMM TASK 28-28-71-400-001).
(10) If you do not know the fault:

Install the removed actuator (2) (Ref. AMM TASK 28-28-71-400-001)
Do the troubleshooting procedure on the ACT forward isolation-valve (1) and the actuator (2) and do the applicable repair procedure.

5. Close-up
Subtask 28-28-00-860-117-C ** ON A/C NOT FOR ALL

A. Put the aircraft back to the serviceable condition.
(1) On ACT refuel panel 801VU, put the REFUEL VALVE selector-switch for the ACT FWD to position NORM.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002)
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Remove the access platform(s).
(5) Close the left MLG door (Ref. AMM TASK 32-12-00-410-001).
(6) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.02 06:17:49 UTC