Removal of the ACT Isolation-Valve Actuator

TASK 28-28-71-000-001-A
Removal of the ACT Isolation-Valve Actuator

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 FUEL SAFETY PROCEDURES.

ZONE: 147
FIN: 92QH ** ON A/C NOT FOR ALL

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	ACCESS PLATFORM 2M (6 FT)
No specific	AR	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
147	MAIN GEAR WELL AND HYDRAULIC COMPARTMENT

C. 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 28-00-00-910-001-A	Fuel Safety Procedures
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
ACT Isolation-Valve Actuator

3. Job Set-up
Subtask 28-28-71-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the APU section of overhead panel 25VU, make sure that the APU/MASTER SW pushbutton switch is released (the ON legend is off).
(3) On the FUEL section of HYD/FUEL panel 40VU, make sure that all the L TK PUMPS and R TK PUMPS pushbutton switches are released (the OFF legends are on).
(4) Put the 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 on overhead panel 20VU, to tell persons not to operate the fire extinguishing system
On the Additional Center Tank (ACT) section of control panel 28VU, to tell persons not to operate the fuel system.

(5) You must obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001) when you do work on the fuel system.
(6) Put the WARNING NOTICE(S) in position to tell persons not to operate the main gear doors.

Subtask 28-28-71-010-050-A ** ON A/C NOT FOR ALL

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

4. Procedure
Subtask 28-28-71-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the ACT Isolation-Valve Actuator

ACT Isolation-Valve Actuator ** ON A/C NOT FOR ALL

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.

(1) Disconnect the electrical connectors (12) from the ACT isolation-valve actuator (1).
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Remove the nut (2), the washer (4) and the screw (5) and disconnect the bonding strap (3) from the mounting flange (7).
(4) Remove the four nuts (8).
(5) Remove the ACT isolation-valve actuator (1) and the mounting flange assembly.
(6) Remove the mounting flange (7) from the ACT isolation-valve actuator (1) as follows:

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.

(a) Cut and remove the lockwire from the screw (9).
(b) Loosen the screw (9) and remove the V-clamp (10).
(c) Remove and discard the O-ring (11) from the mounting flange (7).
(d) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.02 07:03:39 UTC