Removal of the Lower Left Thermocouple Lead Assembly [CFMI]

TASK 77-21-10-000-004-A
Removal of the Lower Left Thermocouple Lead Assembly

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** 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	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

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

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-A	Opening of the Fan Cowl Doors
TASK 78-30-00-481-041-A	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-A	Opening of the Thrust Reverser Doors
Lower Left T495 Sector

3. Job Set-up
Subtask 77-21-10-941-053-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 77-21-10-010-096-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR

Subtask 77-21-10-040-058-A ** ON A/C NOT FOR ALL

C. Make the thrust reverser unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 77-21-10-010-066-A ** ON A/C NOT FOR ALL

D. Open the thrust reverser doors: (Ref. AMM TASK 78-36-00-010-040)
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR

4. Procedure
Subtask 77-21-10-020-053-A ** ON A/C NOT FOR ALL

A. Removal of the Lower Left Thermocouple Lead Assembly (Lower Left T495 Sector)
(1) Cut and remove the lockwire.

NOTE: For engine with EGT sensor (thermocouple) probe brackets repaired, you find a bolt which replaces a stud and a nut (10). A lockwire lock the bolt to a specific washer located on the nut (10).
You can see engraved on the specific washer mark aera, the number of SB CFM56 72-0673.

(2) Disconnect the main junction box lead connector (130) from the lower left T495 sector junction box (parralel junction box) (20).
(3) Remove the parts which attach the lower left T495 as follows:

PRE SB CFM 72-0673

(a) Remove the nuts (10) from the studs (30) on LPT case, between the 7 and 8:15 oclock positions (Detail B).

END OF PRE SB CFM 72-0673

POST SB CFM 72-0673

(b) Remove the bolt (65) from the EGT Sensor (Thermocouple) Probe Bracket Assy on LPT case, at the 7 and 8:15 oclock positions (Detail B).
(c) Remove the nut (10) and the washer ffrom the stud (30). Keep the bolt and the washer.

END OF POST SB CFM 72-0673

(d) Remove the bolt (60) from the bracket (40) on flange S, at the 8:30 o'clock position (Detail C).
(e) Remove the clamp (50).
(f) Remove the bolt (120) on the bracket (90) on lower left T495 sector (20) junction, at the 8 o'clock position (Detail D).
(g) Remove the clamp (110).
(h) Remove the lower extension lead box (100).
(i) Remove the nuts (80) from the flange S, at the 8 o'clock position (Detail D).
(j) Remove the bolt (70) and the bracket (90).
(k) Remove the bolt (10) from the bracket (100) on flange S, at the 7:30 o'clock position (Detail E).
(l) Remove the clamp (160).
(4) Carefully remove the lower left T495 sector (20) from the LPT holes, and from the engine.
(5) Install the PLUG - BLANKING and CAP - BLANKING on all disconnected parts.

[Rev.10 from 2021] 2026.04.02 07:32:52 UTC