Borescope Inspection of the No 4 Bearing Compartment Oil Nozzle Bolts [IAE]

TASK 72-00-00-200-807-A
Borescope Inspection of the No 4 Bearing Compartment Oil Nozzle Bolts

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

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

ZONE: 400

1. Reason for the Job
This task gives the procedure for the borescope inspection of the bolts and tab washers that secure the No. 4 bearing oil nozzle to make sure the bolts and tabs are installed and the tab washers are correctly bent and seated.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 45 and 36 lbf.in (0.51 and 0.41 m.daN )
No specific	Torque wrench: range to between 70 and 60 lbf.in (0.79 and 0.68 m.daN )
No specific	Torque wrench: range to between 85 and 75 lbf.in (0.96 and 0.85 m.daN )
No specific	Torque wrench: range to between 611 and 566 lbf.in (6.90 and 6.40 m.daN )
IAE1R18003	1	WRENCH

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V02-274)	safety cable kit

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
3	GASKET	AIPC 72-42-20-80-050
6	GASKET	AIPC 72-42-20-80-120

E. Referenced Information

REFERENCE	DESIGNATION
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 31-60-00-860-002-A	EIS Stop Procedure
TASK 71-00-00-710-012-B	Test No.3 : Idle Leak Check
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-30-00-440-012-A	Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance
TASK 78-32-00-010-010-A	Opening of the Thrust Reverser Halves
TASK 78-32-00-410-010-A	Closing of the Thrust Reverser Halves
Removal and Installation of the Scavenge Tube and Elbow
Remove and Install Details of the No. 4 Bearing Scavenge Tube
View Looking into No. 4 Scavenge Tube with Elbow and related Hardware removed
Install the Borescope
Cross Section View showing Borescope Path to Scavenge Oil Drain Hole in No. 4 forward Housing
Cross Section View looking down on No. 4 Bearing Compartment showing Oil Nozzle Assembly Bolts relative to Borescope exiting the Scavenge Oil Drain Hole in Bearing Housing
Cross Section View (forward looking aft) showing Orientation of Borescope to view 'Near' Bolt
Cross Section View (forward Looking aft) showing Borescope Path to view 'Far' Bolt
Torque Sequence and Gasket Installation

3. Job Set-up
Subtask 72-00-00-941-175-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 72-00-00-010-250-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.

Subtask 72-00-00-040-125-A ** ON A/C NOT FOR ALL

C. Deactivate the Thrust Reverser

WARNING: MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) Deactivate the thrust reverser hydraulic control unit (HCU) (Ref. AMM TASK 78-30-00-040-012).

Subtask 72-00-00-010-251-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the thrust reverser halves (Ref. AMM TASK 78-32-00-010-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR.

4. Procedure
Subtask 72-00-00-020-080-A ** ON A/C NOT FOR ALL

A. Disconnect the No. 4 bearing scavenge tube assembly from the bifurcation panel and from the No. 4 bearing scavenge elbow.

Removal and Installation of the Scavenge Tube and Elbow ** ON A/C NOT FOR ALL

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(1) Remove the lockwire from the tube nuts at each end of the tube.
(2) Disconnect the clamps from the brackets, but do not remove them from the tube.
(3) Disconnect the No. 4 bearing scavenge tube elbow (8).

Remove and Install Details of the No. 4 Bearing Scavenge Tube ** ON A/C NOT FOR ALL

(a) Remove the four bolts (9) that attach the No. 4 bearing scavenge tube elbow (8) to the boss.
(b) Remove the seal ring (7) from the No. 4 bearing scavenge tube elbow (8) and discard it.
(c) Remove the gasket (6) and discard it.
(d) Remove the two No. 4 bearing scavenge locks (5) and (10).
(e) Remove the sealing sleeve (4) from the inner diameter of the diffuser case boss with the bolts (11).
1 Discard the gasket (3).
(f) Remove the sealing sleeve (13) from the inner diameter of the diffuser case boss with the two screws (12).
(g) Remove the gasket (3) from the inner diameter of the diffuser case boss and discard it.
(h) Remove the heatshield (2) over the outer end of the No. 4 bearing scavenge tube (1).

Subtask 72-00-00-290-128-A ** ON A/C NOT FOR ALL

B. Do a borescope inspection.
(1) Insert the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW into the No. 4 bearing scavenge tube on the forward side of internal stiffener as viewed from entrance to scavenge tube with elbow and related hardware removed.

View Looking into No. 4 Scavenge Tube with Elbow and related Hardware removed ** ON A/C NOT FOR ALL

NOTE: Recommended flexible borescope diameter is 4 mm (0.16 in.) but a maximum diameter of up to 5 mm (0.20 in.) can also be used.

(2) Push the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW through the No. 4 bearing scavenge tube.

Install the Borescope ** ON A/C NOT FOR ALL

CAUTION: DO NOT: - TOUCH OR HIT THE NO. 4 BEARING SCAVENGE STRAINER WITH THE BORESCOPE - PUSH THE BORESCOPE THROUGH THE STRAINER. IF YOU DO, THE BORESCOPE CAN CAUSE DAMAGE TO THE STRAINER OR IT CAN GET CAUGHT IN THE STRAINER. TO REMOVE THE BORESCOPE, IT WILL THEN BE NECESSARY TO REMOVE THE ENGINE TO DISASSEMBLE NO.4 BEARING COMPARTMENT.

(a) Slowly push the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW through the No. 4 bearing scavenge tube until you can see the drain hole in the No. 4 bearing front seal support and the No. 4 bearing scavenge strainer.

Install the Borescope ** ON A/C NOT FOR ALL

Cross Section View showing Borescope Path to Scavenge Oil Drain Hole in No. 4 forward Housing ** ON A/C NOT FOR ALL

(3) Rotate the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW toward the drain hole in the No. 4 bearing front seal support. Push the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW through the drain hole and into the No. 4 bearing compartment.

Cross Section View showing Borescope Path to Scavenge Oil Drain Hole in No. 4 forward Housing ** ON A/C NOT FOR ALL

(a)

Cross Section View looking down on No. 4 Bearing Compartment showing Oil Nozzle Assembly Bolts relative to Borescope exiting the Scavenge Oil Drain Hole in Bearing Housing ** ON A/C NOT FOR ALL

(b) Note the two nozzle attachment bolts will be referred to as 'near' or 'far' bolts related to the proximity of the scavenge oil drain hole.

Cross Section View (forward looking aft) showing Orientation of Borescope to view 'Near' Bolt ** ON A/C NOT FOR ALL

(4) Rotate and push the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW as required to view the near bolt. Pay close attention to the interface between bolt head and tab washer and tab washer and nozzle block.
(5) Examine the bolt and the tab washer.

NOTE: Oil on the nozzle block surface can create reflections that make it seems if there is a gap between the bolt and the nozzle block surface. Try to view the bolt from different angles to reduce the reflection. Also look for evidence that the washer tabs have been bent back away from the bolt head.

(a) The bolt is not there: Reject.
(b) The washer is not there: Reject.
(c) You see a gap between the bolt and the washer (which indicates that the bolt has backed out partially): Reject.
(d) You see a gap between the washer and the nozzle body (which indicates that the bolt and the washer have backed away from nozzle block): Reject.
(e) Other than steps 4.B.(5)(a) thru 4.B.(5)(d): Accept.
(6) Rotate and push the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW further in to inspect the far oil nozzle assembly attachment bolt and tab washer.

Cross Section View (forward Looking aft) showing Borescope Path to view 'Far' Bolt ** ON A/C NOT FOR ALL

NOTE: It is more difficult to get a good view of this bolt. A top down view will verify that the bolt and washer are still present but will not determine if it is loose (you won’t be able to see a gap between the bolt and nozzle block or tab washer). It is necessary to view the bolt at an oblique angle to determine if a gap exists. Also look for evidence that the washer tabs have been bent back away from bolt head.

NOTE: The bolts may also be identified by positioning the borescope so that the Part Number (PN) of the bolt can be read. The PN of the near bolt is ST5014-06 and the PN of the far bolt is ST5013-05.

(a) The bolt is not there: Reject.
(b) The washer is not there: Reject.
(c) You see a gap between the bolt and the washer (which indicates that the bolt has backed out partially): Reject.
(d) You see a gap between the washer and the nozzle body (which indicates that the bolt and the washer have backed away from nozzle block): Reject.
(e) Other than steps 4.B.(6)(a) thru 4.B.(6)(d): Accept.
(7) Carefully remove the BORESCOPE DIA 4 MM (0.16 IN)-FLEXIBLE, FRONT/SIDE VIEW from the engine.

Subtask 72-00-00-420-077-A ** ON A/C NOT FOR ALL

C. Installation of the No. 4 Bearing Scavenge Tube Elbow
(1) Install the No. 4 bearing scavenge tube elbow.

Remove and Install Details of the No. 4 Bearing Scavenge Tube ** ON A/C NOT FOR ALL

(a) Install the heatshield (2) over the outer end of the No. 4 bearing scavenge tube (1).
(b) Install a new AIPC 72-42-20-80-050 GASKET (3) so that it touches the inner diameter of the diffuser case. Do not install a used gasket.
(c) Install the sealing sleeve (13) into the inner diameter of the diffuser case boss. Align the holes in the sealing sleeve with the holes in the boss.
(d) Attach the sealing sleeve with the two screws (12).
(e) Install the two No. 4 bearing scavenge locks (5) and (10).
(f) Install a new AIPC 72-42-20-80-050 GASKET (3) into the inner diameter of the sealing sleeve. Do not install a used gasket.
(g) Install the sealing sleeve (4) into the inner diameter of the diffuser case boss with the bolts (11). Attach the sealing sleeve into the inner diameter of the diffuser case boss.
(h) TORQUE the bolts to between 70 and 60 lbf.in (0.79 and 0.68 m.daN )

.
(i) Install a new AIPC 72-42-20-80-120 GASKET (6). Do not install a used gasket.
(j) Install the seal ring (7) to the No. 4 scavenge tube elbow (8). Make sure the fit of the seal ring to the elbow is correct.
(k) Install the No. 4 scavenge tube elbow (8) to the boss and attach it with the four bolts (9). Use the torque sequence given in

Torque Sequence and Gasket Installation ** ON A/C NOT FOR ALL

in 25 lbf.in (0.28 m.daN) increments until you reach a final TORQUE to between 85 and 75 lbf.in (0.96 and 0.85 m.daN )

on all four bolts.
(2) Connect the No. 4 bearing scavenge tube to the bifurcation panel and the No. 4 bearing scavenge tube elbow.

Removal and Installation of the Scavenge Tube and Elbow ** ON A/C NOT FOR ALL

(a) TORQUE the scavenge tube nuts (with IAE1R18003 WRENCH) to between 611 and 566 lbf.in (6.90 and 6.40 m.daN )

WARNING: USE GOGGLES WHEN YOU REMOVE OR INSTALL SAFETY CABLE. EACH TIME YOU CUT SAFETY CABLE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE SAFETY CABLE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

(b) Safety the scavenge tube nuts with safety cable kit (Material No.V02-274) .
(3) Connect the loop clamps to the No. 4 bearing scavenge tube.
(a) TORQUE the clamp nuts to between 45 and 36 lbf.in (0.51 and 0.41 m.daN )

Subtask 72-00-00-790-050-A ** ON A/C NOT FOR ALL

D. Perform Idle Leak Test
(1) On the center pedestal, on ENG panel 115VU:
(a) Remove the WARNING NOTICE(S) to tell persons not to start the engine.
(2) On the overhead panel, on maintenance panel 50VU:
(a) Release the ENG/FADEC GND PWR/1(2) pushbutton switch, the ON legend goes on.
(b) Remove the WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

WARNING: BEFORE YOU START THE ENGINES FOR THE IDLE LEAK TEST, MAKE SURE THAT ALL HOLD-OPEN RODS ARE SERVICEABLE AND CORRECTLY LOCKED ON EACH ENGINE. IF ONE HOLD-OPEN ROD IS UNSERVICEABLE, CLOSE AND LATCH THE FAN COWL DOORS CORRECTLY. ONE MISSING OR INCORRECTLY LOCKED HOLD-OPEN ROD CAN CAUSE FAN COWL CLOSURE. THIS CAN CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.

(3) Perform an Idle leak check (Ref. AMM TASK 71-00-00-710-012), start with subtask 71-00-00-110-061-A and continue with (and include) subtask 71-00-00-210-091-A.
(a) If there are no leaks, go to para 5.A.
(b) If leak(s) are observed, correct as necessary and perform another leak check (Ref. AMM TASK 71-00-00-710-012), start from subtask 71-00-00-110-061-A and continue with (and include) subtask 71-00-00-210-091-A.

5. Close-up
Subtask 72-00-00-410-214-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) If the thrust reverser halves are open, close the thrust reverser halves (Ref. AMM TASK 78-32-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR.
(3) Activate the thrust reverser hydraulic control unit (HCU) (Ref. AMM TASK 78-30-00-440-012).

Subtask 72-00-00-410-215-A ** ON A/C NOT FOR ALL

B. Close Access
(1) If the fan cowl doors are open, close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.

Subtask 72-00-00-860-136-A ** ON A/C NOT FOR ALL

C. Do the Electronic Instrument System (EIS) stop procedure
(Ref. AMM TASK 31-60-00-860-002).

Subtask 72-00-00-862-062-A ** ON A/C NOT FOR ALL

D. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(2) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:44:26 UTC