Installation of the Exhaust Muffler (131-9(A))

TASK 49-81-41-400-003-A
Installation of the Exhaust Muffler (131-9(A))

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

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

REFERENCE	QTY	DESIGNATION
No specific	Torque wrench: range to between 0.34 and 0.31 m.daN (30.09 and 27.43 lbf.in )
No specific	Torque wrench: range to between 0.93 and 0.81 m.daN (82.30 and 71.68 lbf.in )
No specific	Torque wrench: range to between 2.2 and 1.95 m.daN (16.22 and 14.38 lbf.ft )
No specific	Torque wrench: range to between 2.8 and 2.5 m.daN (20.65 and 18.44 lbf.ft )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.12ABE2)	Corrosion Preventive Compound-Water Displacing Oily Film System
(Material No.14QFB1)	Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
2	COTTER PINS	AIPC 49-81-04-01-080

E. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied 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
TASK 52-41-00-410-001-A	Close the APU Doors after Access
TASK 52-41-18-000-001-A	Removal of the APU Exhaust Access-Fairing
TASK 52-41-18-400-001-A	Installation of the APU Exhaust Access-Fairing
Exhaust Muffler

3. Job Set-up
Subtask 49-81-41-860-056-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) Make sure that there is a warning notice 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).
(5) Make sure that the access platform is in position below the APU compartment.
(6) Make sure that the APU access doors 315AL and 316AR are open (Ref. AMM TASK 52-41-00-010-001).
(7) Make sure that the APU exhaust access-fairing 317AL is removed (Ref. AMM TASK 52-41-18-000-001).

Subtask 49-81-41-865-057-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

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

4. Procedure
Subtask 49-81-41-420-053-A ** ON A/C NOT FOR ALL

A. Installation of the Exhaust Muffler
(1) Make an inspection of the flexible seal (1) for damage or chafing. Replace the flexible seal (1) if necessary.
(2) Make an inspection of the thermal insulation segments for damage. Replace the insulation if necessary.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.
(4) Clean the component interfaces and the adjacent area.
(5) Put the exhaust muffler (7) on the guide rails (10) and put the flexible seal (1) into the guide sleeve (17).
(6) Connect the hot nozzle (18) to the APU exhaust flange (16) with the V-clamp (15).
(7) Secure the V-clamp (15). Torque the clamp lockbolts

of the V-clamp (P/N D49885041200) to between 0.93 and 0.81 m.daN (82.30 and 71.68 lbf.in ) ;
or
of the AEROQUIP V-clamp (P/N 6299342) to between 0.34 and 0.31 m.daN (30.09 and 27.43 lbf.in ) .

(8) Install the two halves of the insulation blanket and safety the stud fasteners with 14QFB1Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -.
(9) Install the bolt (8) the washer (9) from the outer side of the rail.
(10) Install the washer (6) and the nut (5) from the inner side of the support. Do not tighten the nut (5) at this time.
(11) Install the bolt (12) with the bush (11) from the outer side of the rail. Install the washer (4) and the nut (3) from the inner side of the support.
(12) TORQUE the nuts (3) and (5) to between 2.2 and 1.95 m.daN (16.22 and 14.38 lbf.ft )

.
(13) Install the new AIPC 49-81-04-01-080 COTTER PINS (2).
(14) Connect the drain line (13) with the nut (14) to the APU drain-system.
(15) TORQUE the nut (14) to between 2.8 and 2.5 m.daN (20.65 and 18.44 lbf.ft )

.
(16) Apply a thin layer of MOISTURE REMOVER OIL Corrosion Preventive Compound-Water Displacing Oily Film System (Material No.12ABE2) to the exhaust muffler attachment points.

5. Close-up
Subtask 49-81-41-410-052-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-410-001).
(3) Install the APU exhaust access-fairing 317AL (Ref. AMM TASK 52-41-18-400-001).
(4) Set the LIGHT SW 11LJ to the OFF position.
(5) Remove the access platform(s).

Subtask 49-81-41-865-058-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close 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 49-81-41-860-057-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 12:41:54 UTC