Installation of the Compartment Cooling Valve and Cooling Duct (APS 3200)

TASK 49-52-54-400-001-A
Installation of the Compartment Cooling Valve and Cooling Duct (APS 3200)

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
This procedure is only applicable on APU's with a compartment cooling valve installed. These are APU's that have the Mod. 6 Dot mark on the modification plate intact.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	Torque wrench: range to between 16 and 10 lbf.in (0.18 and 0.11 m.daN )
No specific	Torque wrench: range to between 44 and 36 lbf.in (0.50 and 0.41 m.daN )
No specific	Torque wrench: range to between 150 and 135 lbf.in (1.70 and 1.53 m.daN )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

C. 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 49-00-00-860-006-A	APU Shutdown by External Power
TASK 49-00-00-860-006-A-01	APU Shutdown by Batteries
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
Cooling Valve

3. Job Set-up
Subtask 49-52-54-860-051-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Make sure that the aircraft electrical circuits are energized (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) 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 switch 11LJ is set to the on position.

Subtask 49-52-54-865-051-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 49-52-54-020-052-A ** ON A/C NOT FOR ALL

A. Preparation of Replacement Component
(1) Clean and inspect the valve interfaces for damage.
(2) Clean and inspect the ducts and clamps for damage, replace as needed.

Subtask 49-52-54-420-050-A ** ON A/C NOT FOR ALL

CAUTION: DO NOT TORQUE THE V-CLAMP(S) TO MORE THAN THE SPECIFIED VALUE. THIS CAN CAUSE DAMAGE TO THE FLANGE SURFACES.

B. Installation of the Cooling Valve

NOTE: To install the cooling duct only, do steps (7) thru (14).

(1) Position clamp (4) on duct (9) and locate cooling valve (3) on the duct (9).
(2) Install the cooling valve (3) on the fan with the bolts (5).
(3) Attach the pipe (8) to the union (7).
(4) TORQUE the bolts (5) to between 44 and 36 lbf.in (0.50 and 0.41 m.daN )

.
(5) TORQUE the clamp (4) to between 16 and 10 lbf.in (0.18 and 0.11 m.daN )

.
(6) TORQUE the tube connector (8) to between 150 and 135 lbf.in (1.70 and 1.53 m.daN )

.
(7) Install the duct (1) with the clamp (2).
(8) TORQUE the clamp (2) to between 16 and 10 lbf.in (0.18 and 0.11 m.daN )

.
(9) Position the duct (1) on the outlet duct (9).
(10) Install the clamp (4) loosely.
(11) Lightly lubricate the bolts (5) with engine oil.
(12) Install the bolts (5).
(13) Torque the clamp (4) to between 16 and 10 lbf.in (0.18 and 0.11 m.daN )

.
(14) Torque the bolts (5) to between 44 and 36 lbf.in (0.50 and 0.41 m.daN )

Subtask 49-52-54-865-052-A ** ON A/C NOT FOR ALL

C. 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 49-52-54-710-050-A ** ON A/C NOT FOR ALL

D. Test.
(1) Start and operate the APU (Ref. AMM TASK 49-00-00-860-005).
(2) Select bleed air to ON and check cooling valve closes.
(3) Select bleed air OFF and check cooling valve opens.
(4) Stop the APU (Ref. AMM TASK 49-00-00-860-006).

5. Close-up
Subtask 49-52-54-410-050-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 switch 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).
(5) Remove the WARNING NOTICE(S).

Subtask 49-52-54-860-052-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 01:31:34 UTC