Detailed Visual Inspection of the Hydraulic Control Unit Pressure Switch [CFMI]

TASK 78-31-16-210-040-A
Detailed Visual Inspection of the Hydraulic Control Unit Pressure Switch

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	ACCESS PLATFORM 1M(3 FT)
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 71-13-00-410-040-A	Closing of the Fan Cowl Doors
TASK 78-30-00-081-041-A	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-A	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-31-16-000-040-A	Removal of the Hydraulic Control Unit Pressure Switch
TASK 78-31-16-400-040-A	Installation of the Hydraulic Control Unit Pressure Switch
TASK 78-36-00-010-040-A	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-A	Closing of the Thrust Reverser Doors
Pressure Switch

3. Job Set-up
Subtask 78-31-16-941-053-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 78-31-16-010-055-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
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.

Subtask 78-31-16-040-054-A ** ON A/C NOT FOR ALL

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

Subtask 78-31-16-010-056-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 78-31-16-210-051-A ** ON A/C NOT FOR ALL

A. Do a visual inspection of the pressure switch, the related hardware and the pylon electrical connector as follows:

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Inspect the pressure switch for:
A.Damage	No damage allowed	If you find some damage, replace the pressure switch. (Ref. AMM TASK 78-31-16-000-040) and (Ref. AMM TASK 78-31-16-400-040).
B.Crack	No crack allowed	If there is crack, replace the pressure switch. (Ref. AMM TASK 78-31-16-000-040) and (Ref. AMM TASK 78-31-16-400-040).
C.Hydraulic Leakage	No leakage allowed	If there is leakage check bolts for correct torque (Ref. AMM TASK 78-31-16-400-040)
		If the leakage persists, replace the preformed packing (Ref. AMM TASK 78-31-16-000-040) and (Ref. AMM TASK 78-31-16-400-040).
		If the leakage persists, replace the pressure switch (Ref. AMM TASK 78-31-16-000-040) and (Ref. AMM TASK 78-31-16-400-040).
2.Inspect the related hardware of the pressure switch for:
A.Damage	No damage allowed	If you find some damage, replace the defective part. (Ref. AMM TASK 78-31-16-000-040) and (Ref. AMM TASK 78-31-16-400-040).
B.Missing	None allowed	If you find some missing, replace the defective part. (Ref. AMM TASK 78-31-16-000-040) and (Ref. AMM TASK 78-31-16-400-040).
3.Inspect the pylon electrical connector for:
A.Tightness	The blue mark of the pressure switch must be covered by the blue mark of the pylon electrical connector	If the blue mark of the pressure switch is visible, tighten the electrical harness connector with softnose plies.

5. Close-up
Subtask 78-31-16-410-054-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) Close the thrust reverser doors: (Ref. AMM TASK 78-36-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
(3) Remove the access platform(s).

Subtask 78-31-16-440-053-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 78-31-16-410-055-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.02 06:37:58 UTC