Cleaning of the Oil Cooler (APS 3200)

TASK 49-91-44-100-002-A
Cleaning of the Oil Cooler (APS 3200)

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

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	1	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	CAN - SPRAY, NOZZLE EXTENSION EQUIPPED
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	SPRAYING EQUIPMENT - 2 BAR (29 PSI) - 25 L (6,6 US GAL

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.08AJA9)	Aqueous Cleaner-Turbine Engine Gas Path - Legacy
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 49-00-00-860-005-A	APU Start by External Power
TASK 49-00-00-860-005-A-01	APU Start by Batteries
TASK 49-52-41-000-002-A	Removal of the Oil Cooler Outlet Duct (APS 3200)
TASK 49-52-41-400-002-A	Installation of the Oil Cooler Outlet Duct (APS 3200)
TASK 49-52-53-000-001-A	Removal of the Permanent Magnet Generator (PMG) and Cooling Fan Assembly (APS 3200)
TASK 49-52-53-400-001-A	Installation of the Permanent Magnet Generator (PMG) and Cooling Fan Assembly (APS 3200)
TASK 49-91-44-000-003-A	Removal of the Oil Cooler (APS 3200)
TASK 49-91-44-400-003-A	Installation of the Oil Cooler (APS 3200)
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

3. Job Set-up
Subtask 49-91-44-860-053-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the panel 25VU, make sure that the APU MASTER SW pushbutton switch is off.
(3) Put 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).

Subtask 49-91-44-865-066-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 49-91-44-010-057-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT control switch 11LJ to the on position.
(4) Place a drip pan under the oil cooler.
(5) Remove the fan outlet duct assembly (Ref. AMM TASK 49-52-53-000-001).
(6) Remove the oil cooler exhaust duct (Ref. AMM TASK 49-52-41-000-002).

4. Procedure
Subtask 49-91-44-140-050-A ** ON A/C NOT FOR ALL

A. Cleaning of the Installed Oil Cooler
(1) Prepare a cleaning fluid, 2 liters of Aqueous Cleaner-Turbine Engine Gas Path - Legacy (Material No.08AJA9) to 20 liters of demineralized or good quality drinking water.
(2) Put the prepared cleaning fluid into a SPRAYING EQUIPMENT - 2 BAR (29 PSI) - 25 L (6,6 US GAL.
(3) Equip the pressurized container with a CAN - SPRAY, NOZZLE EXTENSION EQUIPPED.
(4) Pressurize the container to 30 psi.
(5) Adjust the nozzle to produce a fine spray.
(6) Direct the spray nozzle into the top of the oil cooler matrix. Spray the oil cooler air passages with the cleaning fluid, maintain a minimum pressure of 20 psi (1.3790 bar).
(7) Let the cleaning fluid dwell on the matrix for 10 to 15 minutes.
(8) Flush the matrix with clean warm water.
(9) Repeat the procedure until the matrix air passages are free of contamination.
(10) Dry the air passages with compressed air at pressure not more than 60 psi (4.1369 bar).
(11) Dry the exterior of the oil cooler with a Textile-Lint free Cotton - (Material No.14SBA1) .
(12) Clean inside the cooler exhaust duct and the fan outlet duct, use a cloth dampened with the cleaning solution. Blow dry with compressed air.
(13) Install the oil cooler exhaust duct (Ref. AMM TASK 49-52-41-400-002).
(14) Install the fan outlet duct assembly (Ref. AMM TASK 49-52-53-400-001).
(15) Make sure that the work area is clean and clear of tools and other items.
(16) Start the APU (Ref. AMM TASK 49-00-00-860-005). If the APU starts and runs and no HOT shutdown occurs, return the APU to service.
(17) If during the APU test a HOT shutdown occurs, do the Subtask that follows.

Subtask 49-91-44-140-051-A ** ON A/C NOT FOR ALL

B. Cleaning of the Uninstalled Oil Cooler.
(1) Remove the oil cooler (Ref. AMM TASK 49-91-44-000-003).
(2) Seal the oil inlet and outlet openings.
(3) Send the oil cooler to the workshop to clean and make sure its cooling efficiency by rig test.
(4) Install the oil cooler (Ref. AMM TASK 49-91-44-400-003).

5. Close-up
Subtask 49-91-44-410-056-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Remove the drip pan that is below the oil cooler.
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Set the LIGHT control switch 11LJ to the off position.
(4) Close the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-410-001).
(5) Remove the access platform(s).

Subtask 49-91-44-865-067-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 49-91-44-860-054-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 aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 01:33:32 UTC