Depressurize the Blue Hydraulic System

TASK 29-10-00-864-003-A
Depressurize the Blue Hydraulic System

WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES.

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

1. Reason for the Job
To make sure that the Blue hydraulic system is depressurized before work is done on the system.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. 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 31-60-00-860-001-A	EIS Start Procedure
TASK 31-60-00-860-002-A	EIS Stop Procedure

3. Job Set-up
Subtask 29-10-00-860-078-A

A. Aircraft Maintenance Configuration
(1) Stop the supply of hydraulic power to the Blue hydraulic system through the ground connections.
(2) If the blue electric pump is in operation:

In the flight compartment (on section 40VU of the overhead panel) push and release the BLUE ELEC PUMP pushbutton (P/BSW).

(3) Make sure that the OFF legend comes on.
(4) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(5) On the ECAM control panel on the center pedestal:

Push the HYD pushbutton (P/BSW). Make sure that the lower (system) display shows the HYD page.

Subtask 29-10-00-865-051-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	HYD/HYD PWR/B WARN/& CTL	2702GJ	C12
123VU	B HYD/ELEC PUMP	2701GJ	AB09

4. Procedure
Subtask 29-10-00-864-052-B

A. Depressurization

NOTE: When the hydraulic pressure supply stops, the pressure decreases quickly to approximately 700 psi / 50 bar. From this value the pressure decreases very slowly to zero (approximately 15 minutes).

(1) Refer to the ECAM indication of the BLUE system pressure and make sure it shows 0.

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(2) If the ECAM indication of the BLUE system pressure does not show 0, operate the rudder to reduce the pressure to zero.

5. Close-up
Subtask 29-10-00-865-052-A

A. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	HYD/HYD PWR/B WARN/& CTL	2702GJ	C12
123VU	B HYD/ELEC PUMP	2701GJ	AB09

Subtask 29-10-00-869-050-A

B. Do the EIS stop procedure
(Ref. AMM TASK 31-60-00-860-002).

Subtask 29-10-00-862-055-A

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

[Rev.10 from 2021] 2026.04.01 00:13:40 UTC