Removal of the Bleed Differential Pressure-Transducer

TASK 36-11-18-000-801-A
Removal of the Bleed Differential Pressure-Transducer

WARNING: MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.

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.

ZONE: 413
ZONE: 423
FIN: 18HA1 ** ON A/C NOT FOR ALL
FIN: 18HA2 ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
413	UPPER FWD PYLON
423	UPPER FWD PYLON
FOR [18HA1] (XDCR-BLEED DIFFERENTIAL PRESS, ENG1)
413AT
FOR [18HA2] (XDCR-BLEED DIFFERENTIAL PRESS, ENG2)
423AT

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 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 71-00-00-860-833-A	Procedure to Prevent Engine Motoring
Bleed-Differential Pressure Transducer ** ON A/C NOT FOR ALL
Bleed Differential Pressure-Transducer ** ON A/C NOT FOR ALL
FOR [18HA1] (XDCR-BLEED DIFFERENTIAL PRESS, ENG1)
TASK 54-52-11-000-805-A	Removal of the Access Skin Panels
FOR [18HA2] (XDCR-BLEED DIFFERENTIAL PRESS, ENG2)
TASK 54-52-11-000-805-A	Removal of the Access Skin Panels

3. Job Set-up
Subtask 36-11-18-861-050-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002) or (Ref. AMM TASK 24-41-00-861-002).

Subtask 36-11-18-941-050-A ** ON A/C NOT FOR ALL

B. Safety Precautions
(1) Make sure that the engine 1(2) shutdown occurred for a minimum of 5 minutes before you do this procedure.
(2) In the cockpit, on AIR COND panel 30VU:
(a) Make sure that the ENG 1(2) BLEED pushbutton switch is released (OFF legend on).
(b) Make sure that the APU BLEED pushbutton switch is released (ON legend off).
(c) Put a WARNING NOTICE(S) in position to tell persons not to operate the pneumatic system.
(3) In the cockpit, on the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR 1(2) pushbutton switch is off.
(b) Put the WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
(4) Do the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).

Subtask 36-11-18-865-050-A ** ON A/C NOT FOR ALL

C. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 18HA1 (XDCRBLEED DIFFERENTIAL PRESS, ENG1)
49VU	AIR BLEED/ENG 1/CTL	2HA1	D11
122VU	AIR BLEED/ENG 1/MONG	3HA1	Z23
FOR FIN: 18HA2 (XDCRBLEED DIFFERENTIAL PRESS, ENG2)
49VU	AIR BLEED/ENG 2/MONG	3HA2	D12
122VU	AIR BLEED/ENG 2/CTL	2HA2	Z22

Subtask 36-11-18-010-050-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Put an ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position at the pylon access panels.
(2) Remove these access panels:
(a) FOR [18HA1] (XDCR-BLEED DIFFERENTIAL PRESS, ENG1)
413AT (Ref. AMM TASK 54-52-11-000-805).
(b) FOR [18HA2] (XDCR-BLEED DIFFERENTIAL PRESS, ENG2)
423AT (Ref. AMM TASK 54-52-11-000-805).

4. Procedure
Subtask 36-11-18-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Bleed Differential Pressure-Transducer
(1) If you use the APU to energize the electrical circuits, stop the APU:

For GTCP 36-300 APU (Ref. AMM D/O 49-00-00-86)
For APS 3200 APU (Ref. AMM D/O 49-00-00-86)
For 131-9(A) APU (Ref. AMM TASK 49-00-00-860-009).

WARNING: MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.

(2) Make sure that you wait for a minimum of 5 minutes until there is no pressure in the bleed-air duct system.

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

(3) Make sure that the temperature of the bleed-air duct system is in the ambient condition.
(4) Disconnect the electrical connector (1) from the transducer (6).
(5) Put a CAP - BLANKING on the disconnected electrical connector (1).
(6) Disconnect the senseline (2) and (3) from the transducer (6).

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT THE PNEUMATIC LINES ON UNIONS.

(7) Disconnect the duct (3) from the transducer (6).
(8) Put a PLUG - BLANKING on the ends of the disconnected senselines (2) and (3) and the transducer (6).
(9) Remove the nuts (9), the washers (5) and the bolts (4).
(10) Remove the clamps (7) and the transducer (6) from the bracket (8).
(11) Remove the transducer (6) from the clamps (7).

Subtask 36-11-18-020-050-B ** ON A/C NOT FOR ALL

A. Removal of the Bleed Differential Pressure-Transducer
(1) If you use the APU to energize the electrical circuits, stop the APU:

For GTCP 36-300 APU (Ref. AMM D/O 49-00-00-86)
For APS 3200 APU (Ref. AMM D/O 49-00-00-86)
For 131-9(A) APU (Ref. AMM TASK 49-00-00-860-009).

WARNING: MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.

(2) Make sure that you wait for a minimum of 5 minutes until there is no pressure in the bleed-air duct system.

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

(3) Make sure that the temperature of the bleed-air duct system is in the ambient condition.
(4) Disconnect the electrical connector (3) from the transducer (6).
(5) Put a CAP - BLANKING on the disconnected electrical connector (3).

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT THE PNEUMATIC LINES ON UNIONS.

(6) Disconnect the senselines (1) and (2) from the transducer (6).
(7) Put a PLUG - BLANKING on the ends of the disconnected senselines (1) and (2) and the transducer (6).
(8) Remove the nuts (9), the bolts (4) and the washers (5).
(9) Remove the clamps (7) and the transducer (6) from the bracket (8).
(10) Remove the transducer (6) from the clamps (7).

[Rev.10 from 2021] 2026.04.01 01:08:47 UTC