Visual Inspection of the Load-Compressor Buffer-Pressure Tube-Assembly (APS 3200)

TASK 49-21-00-200-801-A
Visual Inspection of the Load-Compressor Buffer-Pressure Tube-Assembly (APS 3200)

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

WARNING: LOCK THE MECHANISM OF THE ACCESS DOOR 316AR WITH THE PIP PIN WHEN YOU OPEN THE ACCESS DOOR. THIS WILL PREVENT INJURY.

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

CAUTION: DO NOT APPLY MORE THAN THE SPECIFIED TORQUE. IF YOU DO, YOU CAN CAUSE DAMAGE TO THE TUBES.

ZONE: 315
ZONE: 316

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 5M (16 FT)- ADJUSTABLE
No specific	1	AIR SOURCE 1.7 TO 2 BAR (25 TO 30 PSI) - FILTERED, DRY
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	VACUUM CLEANER
No specific	1	WARNING NOTICE(S)
No specific	Torque wrench: range to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )
No specific	Torque wrench: range to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )
No specific	Torque wrench: range to between 150 and 135 lbf.in (1.70 and 1.53 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03ABA1)	Synthetic base Lubricating Oil-Turbine Engine - -
(Material No.03ABB1)	Synthetic base Lubricating Oil-Turbine Engine Low Temp. -
(Material No.03FAB1)	Mineral Oil base Grease-- Vaseline or Petrolatum -
(Material No.08AJA9)	Aqueous Cleaner-Turbine Engine Gas Path - Legacy

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315	TAIL CONE APU AND ACCESSORY COMPARTMENT
316	TAIL CONE APU AND ACCESSORY COMPARTMENT
315AL, 316AR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
4	PACKING	AIPC 49-21-04-53-030
20	PACKING	AIPC 49-21-04-54-030
21	PACKING	AIPC 49-21-04-54-090

E. 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 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
Load-Compressor Buffer-Pressure Tube-Assembly

3. Job Set-up
Subtask 49-21-00-860-057-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 panel 25VU, make sure that the APU Master Switch pushbutton switch is in the OFF position.
(3) Put the WARNING NOTICE(S) on panel 25VU 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 49-21-00-865-053-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 49-21-00-010-057-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set light switch 11LJ to the ON position.

4. Procedure
Subtask 49-21-00-020-056-A ** ON A/C NOT FOR ALL

A. Removal of the Load-Compressor Buffer-Pressure Tube-Assembly

NOTE: The load-compressor buffer-pressure tube-assembly includes the gearbox Compressor Discharge Pressure (CDP) tube (tube B1 (2)), the forward bearing-seal CDP-tube (tube B2 (18)) and the tee-fitting (1).

(1) Removal of tube B1 (2)
(a) Remove the nut (15), bolt (11) and spacer (13).
(b) Remove the nut (10), bolt (5) and spacer (7).
(c) Remove the clamps (12) and (6).
(d) Remove the clamps (16) (3 locations).
(e) Remove the bolts (3).
(f) Use an auxiliary torque wrench to hold the tee-fitting (1).
(g) Loosen the B-nut of tube B1 (2) and disconnect tube B1 (2) from the tee-fitting (1).
(h) Remove tube B1 (2).
(i) Remove and discard the packing (4).
(2) Removal of tube B2 (18)
(a) Remove the clamp (14).
(b) Remove the bolts (19).
(c) Use an auxiliary torque wrench to hold the tee-fitting (1).
(d) Loosen the B-nut of tube B2 (18) and disconnect tube B2 (18) from the tee-fitting (1).
(e) Remove tube B2 (18).
(f) Remove and discard the packing (20).
(3) Removal of the tee-fitting (1)
(a) Release the nut (23).
(b) Remove the tee-fitting (1) and the retainer (22).
(c) Remove and discard the parking (21).

Subtask 49-21-00-210-052-A ** ON A/C NOT FOR ALL

B. Inspection of the Load-Compressor Buffer-Pressure Tube-Assembly
(1) Do a visual inspection of the two ends of tube B1 (2) and tube B2 (18) for signs of blockage.
(2) Do a visual inspection of the power-section compressor-housing assembly-port (24) and the load-compressor scroll port (25) for signs of blockage.
(3) Do a visual inspection of the connections of the tee-fitting (1) for signs of blockage, cracks and/or air leaks.

NOTE: Blockage of tube B1 (2) or tube B2 (18) is not permitted. Blockage of the power-section compressor-housing assembly-port (24) or the load-compressor scroll port (25) is not permitted. Blockage, cracks and/or air leaks at the connections of the tee-fitting (1) are not permitted.

(4) If there are signs of blockage, replace or clean tube B1 (2) and/or tube B2 (18).
(a) Dry air-cleaning procedure:
1 Blow dry air through tube B1 (2) and/or tube B2 (18) with a AIR SOURCE 1.7 TO 2 BAR (25 TO 30 PSI) - FILTERED, DRY.
(b) Soaking procedure:
1 Put sufficient Aqueous Cleaner-Turbine Engine Gas Path - Legacy (Material No.08AJA9) into a CONTAINER 10 L(2 1/2 USGAL).
2 Refer to the cleaner manufacturer's specification for the soaking time, and soak tube B1 (2) and/or tube B2 (18) in the cleaning solution, or soak for a minimum of 15 minutes.
3 Blow dry air through tube B1 (2) and/or tube B2 (18) with the AIR SOURCE 1.7 TO 2 BAR (25 TO 30 PSI) - FILTERED, DRY to make sure that the blockage is removed.
(5) If there are signs of blockage in the power-section compressor-housing assembly-port (24) and/or the load-compressor scroll port (25):
(a) Use a Punch - non-metallic to remove the blockage and use a VACUUM CLEANER while you work in the area to prevent contamination of the APU.
(6) If there are cracks and/or air leaks at the connections of the tee-fitting (1), replace the tee-fitting (1).
(7) If you do not find blockage with the visual inspection, blow dry air through tube B1 (2) and/or tube B2 (18) with the AIR SOURCE 1.7 TO 2 BAR (25 TO 30 PSI) - FILTERED, DRY to make sure that there is no blockage. If necessary, do the cleaning procedure given in the visual inspection.

Subtask 49-21-00-420-056-A ** ON A/C NOT FOR ALL

C. Installation of the Load-Compressor Buffer-Pressure Tube-Assembly
(1) Apply Mineral Oil base Grease-- Vaseline or Petrolatum - (Material No.03FAB1) to the new AIPC 49-21-04-53-030 PACKING (4), the new AIPC 49-21-04-54-030 PACKING (20) and the new AIPC 49-21-04-54-090 PACKING (21).
(2) Apply Synthetic base Lubricating Oil-Turbine Engine - - (Material No.03ABA1) or Synthetic base Lubricating Oil-Turbine Engine Low Temp. - (Material No.03ABB1) to the bolts (3), (5), (11) and (19).
(3) Installation of the tee-fitting (1)
(a) Install the tee-fitting (1), the retainer (22), the packing (21) and the nut (23) in the port (17).
(b) Align the tee-fitting (1) for the installation of tube B1 (2) and tube B2 (18).
(c) Tighten the nut (23) with your hand.
(d) TORQUE the nut (23) to between 150 and 135 lbf.in (1.70 and 1.53 m.daN )

.
(4) Installation of tube B2 (18)
(a) Install the packing (20) and tube B2 (18) in the port (25).
(b) Install the bolts (19).
(c) Tighten the bolts (19) with your hand.
(d) TORQUE the bolts (19) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(e) Connect tube B2 (18) to the tee-fitting (1).
(f) Use an auxiliary torque wrench to hold the tee-fitting (1).
(g) Tighten the B-nut of tube B2 (18) with your hand.
(h) TORQUE the B-nut of tube B2 (18) to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )

.
(5) Installation of tube B1 (2)
(a) Install the packing (4) and tube B1 (2) in the port (24).
(b) Install the bolts (3).
(c) Tighten the bolts (3) with your hand.
(d) TORQUE the bolts (3) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(e) Connect tube B1 (2) to the tee fitting (1).
(f) Use an auxiliary torque wrench to hold the tee-fitting (1).
(g) Tighten the B-nut of tube B1 (2) with your hand.
(h) TORQUE the B-nut of tube B1 (2) to between 100 and 90 lbf.in (1.13 and 1.02 m.daN )

.
(6) Install the clamps (16) (3 locations).
(7) Install the spacer (7), clamp (6), bolt (5) and nut (10) to make one assembly with the clamps (8) and (9).
(8) Install the spacer (13), clamp (12), bolt (11) and nut (15) to make one assembly with the clamp (14).
(9) Tighten the nuts (10) and (15) with your hand.
(10) TORQUE the nuts (10) and (15) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

5. Close-up
Subtask 49-21-00-410-056-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 light switch 11LJ to the OFF position.
(3) Close the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).

Subtask 49-21-00-865-054-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 49-21-00-860-058-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(2) Remove the WARNING NOTICE(S).
(3) Put the aircraft back to its initial configuration.

[Rev.10 from 2021] 2026.04.01 01:28:56 UTC