Installation of the Oil Cooler (131-9(A))

TASK 49-91-44-400-004-A
Installation of the Oil Cooler (131-9(A))

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 22 and 18 lbf.in (0.25 and 0.20 m.daN )
No specific	Torque wrench: range to between 55 and 45 lbf.in (0.62 and 0.51 m.daN )
No specific	Torque wrench: range to between 110 and 90 lbf.in (1.24 and 1.02 m.daN )
No specific	Torque wrench: range to between 0.5 and 0.4 m.daN (44.25 and 35.40 lbf.in )

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 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 49-00-00-860-008-A	APU Start by External Power
TASK 49-00-00-860-008-A-01	APU Start by Batteries
TASK 49-00-00-860-009-A	APU Shutdown by External Power (131-9(A))
TASK 49-00-00-860-009-A-01	APU Shutdown by Batteries (131-9(A))
TASK 49-90-00-600-007-A	Check Oil Level and Replenish (131-9(A))
TASK 49-91-44-400-802-A	Installation of the Oil-Cooler Transfer Tubes (131-9(A))
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
Oil Cooler

3. Job Set-up
Subtask 49-91-44-860-063-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 are open (Ref. AMM TASK 52-41-00-010-001).
(7) Make sure that the LIGHT control SW 11LJ is set to the ON position.

Subtask 49-91-44-865-071-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 49-91-44-420-054-A ** ON A/C NOT FOR ALL

A. Installation of the Oil Cooler

NOTE: The oil leaks into the APU compartment can cause smell in cabin.

(1) Remove the blanking plugs from the oil cooler and the oil pipes.
(2) Position the oil cooler (2) and move it to the aft APU side until the captive nuts (6) are in the correct position on the oil cooler engine support.
(3) Attach the oil cooler (2) with the bolts (5).
(4) Install the oil cooler (2) with the captive bolts (1).
(5) TORQUE the captive bolts (1) to between 22 and 18 lbf.in (0.25 and 0.20 m.daN )

.
(6) TORQUE the bolts (5) to between 55 and 45 lbf.in (0.62 and 0.51 m.daN )

NOTE: See view B.

(7) Torque the captive nuts (6) to between 110 and 90 lbf.in (1.24 and 1.02 m.daN )

NOTE: See view C.

(8) Connect the oil-cooler transfer tubes to the oil cooler (2) (Ref. AMM TASK 49-91-44-400-802).
(9) Connect the air outlet duct (4) to the oil cooler (2) with the clamp (3).
(10) TORQUE the clamp (3) to between 0.5 and 0.4 m.daN (44.25 and 35.40 lbf.in )

NOTE: To prevent damage to the ducts, do not overtighten the clamp (3).

Subtask 49-91-44-865-072-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 49-91-44-710-054-A ** ON A/C NOT FOR ALL

C. Leak Test
(1) Start the APU to circulate oil through the oil cooler. (Ref. AMM TASK 49-00-00-860-008)
(2) Stop the APU (Ref. AMM TASK 49-00-00-860-009).
(3) Add oil to correct level. (Ref. AMM TASK 49-90-00-600-007)
(4) Examine the oil cooler (2) and pipe connections for leaks. No leaks are permitted.

5. Close-up
Subtask 49-91-44-410-058-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) Set the LIGHT control SW 11LJ to the OFF position.
(3) Close the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).

Subtask 49-91-44-860-064-A ** ON A/C NOT FOR ALL

B. 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 01:33:29 UTC