Removal of the Thermocouples (131-9(A))

TASK 49-72-15-000-002-A
Removal of the Thermocouples (131-9(A))

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

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 4M (13 FT)-ADJUSTABLE
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
315AL, 316AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 52-41-00-010-001-A	Open the APU Doors for Access
Thermocouples

3. Job Set-up
Subtask 49-72-15-860-059-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) On the panel 25VU, make sure that the APU MASTER SW p/bsw is OFF.
(3) Put a WARNING NOTICE(S) in the cockpit to tell persons not to start the APU.
(4) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).

Subtask 49-72-15-865-057-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-72-15-010-053-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL 316AR and (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT SW 11LJ to the ON position.

4. Procedure
Subtask 49-72-15-020-052-A ** ON A/C NOT FOR ALL

A. Removal of the Thermocouples
(1) Remove the nuts (5) and (6) and disconnect the electrical connections (4).
(2) Loosen the nuts (1) and turn the thermocouple (3) to disengage the mounting plate from the studs and pull the thermocouple (3) out of the APU.
(3) Remove and discard the gasket (2).
(4) Install the PLUG - BLANKING on the thermocouple mounting flange.

[Rev.10 from 2021] 2026.04.01 12:42:53 UTC