Removal of the Air/Oil Heat Exchanger (AOHX) [PW11]

TASK 79-21-11-000-802-A
Removal of the Air/Oil Heat Exchanger (AOHX)

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

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

ZONE: 400
FIN: 6002EM ** ON A/C NOT FOR ALL

1. Reason for the Job
Use this procedure to remove the engine Air/Oil Heat Exchanger (AOHX).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	1	CONTAINER 20L (5 USGAL)
No specific	AR	COVER - PROTECTION
No specific	1	STRAP-227 KG(500 LB),NYLON
PWA211312	1	INSTALLATION FIXTURE

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-21-61-000-802-A	Removal of the Integrated Drive Generator (IDG) Power Feeder-Cables
TASK 24-21-61-000-803-A	Removal of the AC Generator Control-Harness
TASK 71-00-00-860-832-A	Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 73-11-48-000-803-A	Removal of the Return Fuel Lines
TASK 73-21-69-000-802-A	Removal of the EEC Wiring Harness (WC10)
TASK 73-21-70-000-802-A	Removal of the Electronic Engine Control (EEC) Wiring Harness (WC11)
TASK 77-21-61-000-802-A	Removal of the Exhaust Gas Temperature (EGT) (T5/T3) Wiring Harness (WC05)
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
TASK 79-11-02-000-801-A	Removal of the Oil Tank Cap and Filler Neck
TASK 79-21-12-000-801-A	Removal of the Air/Oil Heat Exchange Bellows Seal
Engine AOHX - (Removal Method One)
Engine AOHX - (Removal Method Two)
Engine AOHX - (Removal Method Two)
Engine AOHX - (Removal Method Two)
Engine AOHX - (Disassemble The Heat Exchanger)
Engine AOHX - (Oil Tank Cap)

3. Job Set-up
Subtask 79-21-11-941-052-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).

Subtask 79-21-11-010-054-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL, 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR.
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.

Subtask 79-21-11-040-052-A ** ON A/C NOT FOR ALL

C. Deactivation of the Thrust Reverser for Ground Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-805).

Subtask 79-21-11-010-055-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL, 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL, 462AR.

4. Procedure

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE OIL SYSTEM AND USE SUFFICIENT PROTECTION FOR THE HANDS AND EYES. THE OIL IS HOT AND CAN CAUSE BURNS.

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

Subtask 79-21-11-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the AOHX
(1) Find the AOHX assembly (1) at approximately the 10 o'clock position on the diffuser case.
(2) Make sure that the oil system is not pressurized as follows:
(a) Wait five minutes after engine shutdown.
(b) Open the oil tank cap (Ref. AMM TASK 79-11-02-000-801).
(c) Close the oil tank cap (Ref. AMM TASK 79-11-02-000-801).
(3) Prepare the AOHX assembly as follows:
(a) Remove the Return To Tank (RTT) tube from the engine as necessary (Ref. AMM TASK 73-11-48-000-803).
(b) Remove the Integrated Drive Generator (IDG) power feeder cables from the engine as necessary (Ref. AMM TASK 24-21-61-000-802).
(c) Remove the Exhaust Gas Temperature (EGT) wiring harness (WC05) from the engine as necessary (Ref. AMM TASK 77-21-61-000-802).
(d) Remove the Electronic Engine Control (EEC) wiring harness (WC11) from the engine as necessary (Ref. AMM TASK 73-21-70-000-802).
(e) Remove the EEC wiring harness (WC10) from the engine as necessary (Ref. AMM TASK 73-21-69-000-802).
(f) Remove the aircraft generator-control harness from the pylon interface panel and engine as necessary (Ref. AMM TASK 24-21-61-000-803).
(4) Remove the AOHX assembly (1) (Method One) as follows:
(a) Remove the two bolts (8) and the two washers (9) that attach the AOHX assembly (1) to the bracket.
(b) Remove the bolt (5), bushing (6) and nut (7) from the lower rear connecting-link.
(c) Remove the bolt (24), bushing (3) and nut (23) from the bracket assembly.
(d) Remove the bolt (5), bushing (6) and nut (7) from the upper rear connecting-link.
(e) Remove the bolt (2), bushing (3) and nut (4) from the bracket assembly.
(f) Put the CONTAINER 20L (5 USGAL) under the tubes (LP56) and (LP57).
(g) Remove the three bolts (21) and the bracket (20) from the tube (LP57).
(h) Remove the three bolts (21) and the bracket (22) from the tube (LP56).
(i) Remove the two seals (19).
(j) Remove the AOHX from the engine:

WARNING: BE CAREFUL WHEN YOU REMOVE/INSTALL THE AIR/OIL HEAT EXCHANGER ASSEMBLY FROM/ON THE ENGINE. THE AIR/OIL HEAT EXCHANGER IS HEAVY (APPROXIMATELY 75 LBS (34 KG)) AND IF IT FALLS, IT CAN CAUSE INJURY TO PERSONNEL OR DAMAGE TO THE ENGINE.

1 Lift the AOHX assembly (1) to highest position possible below the thrust reverser and then move the bottom of the AOHX assembly (1) outboard.
2 Remove the AOHX assembly (1) from the engine and put the AOHX assembly (1) on a work surface.
(5) Remove AOHX assembly (1) with the PWA211312 INSTALLATION FIXTURE (Method Two) as follows:
(a) Move the PWA211312 INSTALLATION FIXTURE from the aft of the engine under the left thrust reverser.
(b) Use the foot brake to secure the PWA211312 INSTALLATION FIXTURE next to the engine.
(c) Remove the pin from the second post, move the head to the first post and install the pin.
(d) Use the PWA211312 INSTALLATION FIXTURE height hand wheel to lift the head to the highest position possible.
(e) Use the tilt hand wheel to tilt the head until the support block is aligned with the flanges on the AOHX assembly (1).
(f) Use the height hand wheel and the slide hand wheel to move the head until the support block is against the AOHX assembly (1) flanges.
(g) Loosen the four captive bolts to open the four clamps.
(h) Align the four support block holes to four of the flange bolts.
(i) Tighten the four captive bolts to safety the four clamps to the AOHX assembly (1) flanges.
(j) Remove the two bolts (8) and the two washers (9) that attach the AOHX assembly (1) to the bracket.
(k) Remove the bolt (5), bushing (6) and nut (7) from the lower rear connecting-link.
(l) Remove the bolt (24), bushing (3) and nut (23) from the bracket assembly.
(m) Remove the bolt (5), bushing (6) and nut (7) from the upper rear connecting-link.
(n) Remove the bolt (2), bushing (3) and nut (4) from the bracket assembly.
(o) Put the CONTAINER 20L (5 USGAL) under the tubes (LP56) and (LP57).
(p) Remove the three bolts (21) and the bracket (20) from the tube (LP57).
(q) Remove the three bolts (21) and the bracket (22) from the tube (LP56).
(r) Remove the two seals (19).
(s) Remove the AOHX from the engine:

1 Use the height, slide and tilt hand wheels to lift the AOHX assembly (1) to the highest position possible and remove it from the engine.
2 Lower the AOHX assembly (1) with the height hand wheel to just above the support table height.
3 Remove the pin from the first post, move the head to the second post and install the pin.
4 Use the slide and tilt hand wheels to align the AOHX assembly (1) with the support table.
5 Use the height hand wheel to lower the AOHX assembly (1) onto the support table.
6 Install the strap to the support table and safety the AOHX assembly (1).
7 Disengage the brake on the PWA211312 INSTALLATION FIXTURE.
8 Move the fixture:

CAUTION: DO NOT MOVE THE AIR/OIL HEAT EXCHANGER WHEN IT IS IN THE UP POSITION. IF YOU DO NOT OBEY THIS CAUTION, DAMAGE TO THE PARTS CAN OCCUR.

CAUTION: WHEN YOU MOVE THE TOOL OR THE AIR/OIL HEAT EXCHANGER, BE CAREFUL NOT TO HIT THE ENGINE. IF YOU DO NOT OBEY THIS PRECAUTION, DAMAGE TO THE ENGINE OR PARTS CAN OCCUR.

a Move the PWA211312 INSTALLATION FIXTURE and the AOHX assembly (1) aft of the engine.
9 Loosen the four captive bolts and use the slide hand wheel to remove the support block from the AOHX assembly (1).
10 Remove the strap from the AOHX assembly (1).
11 Install the STRAP-227 KG(500 LB),NYLON on the AOHX assembly (1).
12 Attach the hoist to the STRAP-227 KG(500 LB),NYLON.
13 Remove the AOHX assembly (1) from the support block and put on a workbench with the hoist.
14 Remove the STRAP-227 KG(500 LB),NYLON from the hoist and AOHX assembly (1).
(6) Disassemble the AOHX assembly (1) as follows:
(a) Remove the three bolts (37) and the bracket (38) from the air-cooling intake duct (AD01) (36).
(b) Remove the 12 bolts (37) and the air-cooling intake duct (AD01) (36) from the AOHX (35).
(c) Remove the four nuts (41) and the bracket (40) from the air-cooling exhaust duct (AD02) (39).
(d) Remove the bellows seal from the air-cooling exhaust duct (AD02) (39) if necessary (Ref. AMM TASK 79-21-12-000-801).
(e) Remove the 14 bolts (34) and the air-cooling exhaust duct (AD02) (39) from the AOHX (35).
(f) Remove the two bolts (51) and the two washers (52) from the bracket (53) and air-cooling exhaust duct (AD02) (39).
(g) Remove the two bolts (57), the two washers (56) and the bracket (53) from the bracket (54).
(h) Remove the two bolts (55) and the bracket (54) from the air-cooling exhaust duct (AD02) (39).
(7) Examine the assembly for foreign objects, damage and correct assembly.
(8) Installation of the protection covers:

CAUTION: INSTALL PROTECTION COVERS ON ALL THE OPENINGS IMMEDIATELY TO PREVENT DAMAGE TO THE ENGINE.

(a) Make sure that you install all the necessary COVER - PROTECTION to prevent damage to the engine.

[Rev.10 from 2021] 2026.04.01 03:41:43 UTC