Removal of the Exhaust Gas Temperature (EGT) Sensor 3 [CFML]

TASK 77-21-10-000-804-A
Removal of the Exhaust Gas Temperature (EGT) Sensor 3

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.

ZONE: 400
FIN: 4012KS31
FIN: 4012KS32

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	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
Exhaust Gas Temperature (EGT) Sensor 3

3. Job Set-up
Subtask 77-21-10-941-073-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 and 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 77-21-10-010-107-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

Subtask 77-21-10-040-085-A

C. Deactivation of the Thrust Reverser 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 maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 77-21-10-010-108-A

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

4. Procedure
Subtask 77-21-10-020-066-A

A. Removal of the Exhaust Gas Temperature (EGT) Sensor 3

CAUTION: DO NOT REMOVE THE CAPTIVE NUTS FROM THE LEADS. DAMAGE CAN OCCUR TO THE LEADS OR THE CAPTIVE NUTS.

(1) Loosen the large terminal tag on the EGT harness 2 lead (42).
(2) Loosen the small terminal tag on the EGT harness 2 lead (43).
(3) Remove the lead (42) from the EGT sensor 3 (41).
(4) Remove the lead (43) from the EGT sensor 3 (41).
(5) Removal of the lockwire

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 two bolts (44) that attach the EGT sensor 3 (41) to the turbine center frame (4).
(6) Remove the two bolts (44) that attach the EGT sensor 3 (41) to the turbine center frame (4).
(7) Remove the EGT sensor 3 (41) from the engine.
(8) Remove and discard the gasket (45).
(9) Install COVER - PROTECTION and CAP - PROTECTION on all open ports, open tubes, open hoses and connectors.

[Rev.10 from 2021] 2026.04.02 07:41:37 UTC