Hydraulic Pump Depressurization Function (Menu Mode) [CFML]

TASK 73-29-00-740-811-A
Hydraulic Pump Depressurization Function (Menu Mode)

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.

CAUTION: DO NOT ENTER A FLIGHT NUMBER IN THE CFDIU. IF YOU DO, THE MENU MODE WILL STOP WHEN YOU START THE OTHER ENGINE.

ZONE: 400

1. Reason for the Job
The menu mode hydraulic pump depressurization test allows the operator to test the aircraft hydraulic pressure system by depressurizing the Engine Driven Pump (EDP) while the engine is at idle.
2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS

B. 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 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
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 31-32-00-860-012-A	Procedure to Get Access to the SYSTEM REPORT/TEST/ENG Page
Special Functions Menu Screen Format
Hydraulic Pump Depressurization Test
Function Terminated

3. Job Set-up
Subtask 73-29-00-861-073-A

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

Subtask 73-29-00-865-086-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
49VU	ENGINE/1/FADEC A/AND EIU 1	2KS1	A04
121VU	ENGINE/ENG1/FADEC B/AND EIU 1	4KS1	R40
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
49VU	ENGINE/2/FADEC A/AND EIU 2	2KS2	A05
121VU	ENGINE/ENG2/FADEC B/AND EIU2	4KS2	R41

Subtask 73-29-00-866-050-A

C. Aircraft Maintenance Configuration
(1) On ENG panel 115VU:
(a) Make sure that the ENG MASTER switch 1(2) is set to OFF.
(b) Make sure that the ENG/MODE rotary selector-switch is set to NORM.
(2) On the ENG section of maintenance panel 50VU:
(a) Release the FADEC GND PWR1(2) pushbutton switch. The ON legend of this pushbutton switch comes on.
1 After the FADEC is energized, wait ten seconds before you start the test. If you do not wait ten seconds, the interactive mode stops the EEC self-test and this can cause unwanted faults.
(3) On the left or right MCDU, get the SYSTEM REPORT/TEST/ENG page (Ref. AMM TASK 31-32-00-860-012).

4. Procedure
Subtask 73-29-00-710-076-A

A. General
(1) The menu mode hydraulic pump depressurization test allows the operator to test the aircraft hydraulic pressure system. During the test, the engine runs at idle speed, and the EDP depressurization solenoid is energized. The operator then verifies the drop in hydraulic pressure. Next, the EDP depressurization solenoid is de-energized and the operator verifies that hydraulic pressure is restored. The hydraulic pressure is reported through the cockpit displays, not via the Menu Mode screens. Other than this function, EDP depressurization is only performed during in-flight start attempts to unload the engine for an easier start.

Subtask 73-29-00-740-053-A

CAUTION: DO NOT ENTER A FLIGHT NUMBER IN THE CFDIU. IF YOU DO, THE MENU MODE WILL STOP WHEN YOU START THE OTHER ENGINE.

B. Do the hydraulic pump depressurization test

NOTE: : The EEC will not enter the menu mode (interactive mode) after an enquire command from the CFDS (Centralized Fault Display System) when any of the following conditions are set:

N2 more than ten percent or invalid
Engine not off
Engine not in default start state
TLA (Throttle Lever Angle) not at idle or invalid
Aircraft in the air
MASTER lever ON or invalid
BITE command code input label invalid.

NOTE: The EEC will abort the Hydraulic Pump Depressurization function and display the FUNCTION TERMINATED screen when any of the following conditions occur:

N2 is greater than 75 percent or invalid
N2 is greater than 55 percent for 10 minutes or more
N2 drops below 20 percent after going above 20 percent
N2 is less than 20 percent for two minutes during crank or start phase
You enter in the interactive mode of the other channel
RETURN key is selected while the test is running.

NOTE: EEC Menu Mode will be terminated without displaying a termination screen if any of the following conditions occur:

The RETURN key is selected on the main menu screen
Engine start is detected
Mach is greater than 0.12 or invalid
Aircraft indicates it is in air
Idle Test or Hydraulic Pump Depressurization is active but the TLA is not at idle or is invalid.

ACTION	RESULT
1.Initialize Menu Mode on the applicable engine and EEC by selecting FADEC XY (X = Engine Position, Y = Channel Designation)
2.From the Menu Mode main menu (SCREEN 1), push the key adjacent to SPECIAL FUNCTIONS (2R).	The SPECIAL FUNCTIONS menu is shown (SCREEN 2).
3.From the SPECIAL FUNCTIONS page (SCREEN 2), select the key adjacent to HYD PUMP DEPRESS (4R).	The HYDR PUMP DEPRESS FUNC caution screen is displayed (SCREEN 3).
4.From the HYDR PUMP DEPRESS FUNC caution page, select key 5R to start the test.	The HYDR PUMP DEPRESS FUNC engine start screen is displayed (SCREEN 4).
5.Follow the AMM procedure to start the engine. Set Start switch to IGN/START and Master Lever to ON.	Test begins when engine reaches idle power (SCREEN 5) is displayed when the test begins.
Monitor hydraulic pressure.	NOTE: Once the engine reaches idle, the EEC requests the aircraft to energize the EDP depressurization solenoid for approximately 45 seconds (hydraulic pressure should drop). Then the EDP depressurization solenoid is de-energized and the test continues for approximately 45 seconds (hydraulic pressure should rise). The hydraulic depressurization test takes approximately 90 seconds to complete. NOTE: The EEC will not report hydraulic pressure faults. After the depressurization test is completed, the FUNCTION COMPLETED screen is displayed (SCREEN 6).
6.Once the HYDR PUMP DEPRESS FUNC test completed screen is displayed, verify that hydraulic pressure is restored and return the cockpit settings as indicated on SCREEN 6: Set the Master Lever to OFF. Set the Start switch to NORM. Press the key adjacent to RETURN (6L) to return to the SPECIAL FUNCTIONS menu. If the FUNCTION TERMINATED screen is displayed, restore the cockpit settings as indicated on SCREEN 5: Set the Master Lever to OFF. Set the Start switch to NORM. Press the key adjacent to RETURN (6L) to return to the SPECIAL FUNCTIONS menu.	The SPECIAL FUNCTIONS menu is shown (SCREEN 2).

5. Close-up
Subtask 73-29-00-860-103-A

A. Put the aircraft back to its initial configuration.
(1) On the ENG section of maintenance panel 50VU:
(a) Release the FADEC GND PWR 1(2) pushbutton switch (the ON legend goes off).
(2) On the overhead panel, on the ADIRS CDU, set the three OFF/NAV/ATT selector switches to OFF.
(3) Remove the WARNING NOTICE(S).

Subtask 73-29-00-862-073-A

B. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 03:06:11 UTC