Removal of the Electrical Harness from the Pylon to the Environmental Control System (ECS) Valves [CFML]

TASK 71-52-43-000-804-A
Removal of the Electrical Harness from the Pylon to the Environmental Control System (ECS) Valves

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 70-70-00-910-804-A	Electrical Standard Practices
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
Electrical Harness from the Pylon to the Environmental Control System (ECS) Valves

3. Job Set-up
Subtask 71-52-43-941-056-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 71-52-43-010-087-A

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.

Subtask 71-52-43-040-073-A

C. Deactivation of the Thrust Reverser System for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for nacelle maintenance (Ref. AMM TASK 78-30-00-040-807).

Subtask 71-52-43-010-088-A

D. Get Access
(1) Open the right thrust-reverser cowl-door (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
462AR

4. Procedure
Subtask 71-52-43-020-064-A

A. Removal of the Electrical Harness from the Pylon to the Environment Control System (ECS) Valves disconnected connectors.
(1) Before you remove the harness (5), make a record of the harness routing to help during installation.
(2) Disconnect the electrical connectors as follows: (Ref. AMM TASK 70-70-00-910-804)
(a) Disconnect the electrical connector (2) from the receptacle on the High Pressure Valve (HPV) (1).
(b) Disconnect the electrical connector (7) from the receptacle on the Pressure Relief Valve (PRV) (8).
(c) Disconnect the electrical connector (18) from the receptacle on the pylon interface (19).
(3) Disconnect the P-clamps from the harness (5) at two locations as follows:
(a) Remove the bolt (4) from the P-clamp (6) and the support bracket (3).
(b) Remove the bolt (13) from the P-clamp (11) and the support bracket (12).
(4) Remove the harness (5) from the fire seal (17) as follows:
(a) Remove the four screws (16) and the pylon cover (15) from the engine.
(b) Remove the outboard half of the fire seal (17).
(c) Remove the harness (5) from the fire seal (17).
(5) Pull the harness out of the spring clips on the support brackets (3), (9), (10) and (12).
(6) Remove the harness (5) from the engine.
(7) Make a written record of the location and position of the P-clamps (6) and (11) on the harness (5) to help during installation.
(8) Remove the P-clamps (6) and (11) from the harness (5).
(9) Install COVER - PROTECTION and CAP - PROTECTION on all the open ports, open tubes, open hoses and

[Rev.10 from 2021] 2026.04.01 02:36:39 UTC