Removal of the Exhaust Gas Temperature (EGT) Probe [PW11]

TASK 77-21-21-000-801-A
Removal of the Exhaust Gas Temperature (EGT) Probe

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

FIN: 4060KS ** ON A/C NOT FOR ALL
FIN: 4061KS ** ON A/C NOT FOR ALL
FIN: 4062KS ** ON A/C NOT FOR ALL
FIN: 4063KS ** 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	1	ACCESS PLATFORM 1M(3 FT)
No specific	1	BRUSH - BRISTLED
No specific	1	COVER - PROTECTION

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.P05-005)	lint-free cotton cloth
(Material No.P11-014)	isopropyl alcohol

C. Work Zones and Access Panels

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

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-860-832-A	Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
Removal of the Exhaust Gas Temperature (EGT) Probe

3. Job Set-up
Subtask 77-21-21-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).

Subtask 77-21-21-010-050-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 77-21-21-040-050-A ** ON A/C NOT FOR ALL

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 78-30-00-040-805).

Subtask 77-21-21-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
- 451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
- 461AL 462AR

4. Procedure
Subtask 77-21-21-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the EGT Thermocouple

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

CAUTION: DO NOT BEND OR TWIST THE EGT HARNESS LEADS WHEN YOU REMOVE OR INSTALL THEM. IF YOU BEND OR TWIST THE EGT HARNESS LEADS, YOU CAN CAUSE DAMAGE TO THE CABLE.

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

(1) Find the four EGT probes (2) attached to the Turbine Exhaust Case (TEC) at approximately the 2, 4, 8 and 10 o'clock positions.

NOTE: Use this procedure for each EGT probe.

(2) Disconnect the EGT wiring harness (WC05) from the probe (2) as follows:
(a) Clean the debris from the threads of the two probe (2) studs with a BRUSH - BRISTLED or equivalent.
(b) Loosen the harness (WC05) captured nuts and remove from the two probe (2) studs.
(c) Use a lint-free cotton cloth (Material No.P05-005) and isopropyl alcohol (Material No.P11-014) to clean the studs and captured nuts.
(3) Remove the probe (2) as follows:
(a) Remove the two bolts (1) that attach the probe (2) to the TEC boss.
(b) Remove the probe (2) from the TEC boss.
(4) Installation of protection covers

CAUTION: INSTALL PROTECTION COVERS ON ALL THE OPENINGS IMMEDIATELY TO PREVENT DAMAGE TO THE ENGINE.

(a) Make sure that you install all the necessary COVER - PROTECTION to prevent engine damage.

[Rev.10 from 2021] 2026.04.01 03:18:55 UTC