Loss of the Correct Quantity in the Blue Hydraulic Reservoir

TASK 29-12-00-810-803-A
Loss of the Correct Quantity in the Blue Hydraulic Reservoir

1. Possible Causes

LOW LEVEL SWITCH
wiring
DIODE (1156VD)
QUANTITY INDICATOR - TRANSMITTER
hydraulic lines
SDAC-1 [1WV1]
SDAC-2 [1WV2]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 31-54-00-810-831-A	Loss of the BLUE RSVR QTY Input of the SDAC 1
TSM TASK 31-54-00-810-832-A	Loss of the BLUE RSVR QTY Input of the SDAC 2
AMM 12-32-28-281-001	Drain Water Content
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 29-00-00-280-002	Check of the Internal Leakage of the Blue Hydraulic System
AMM 29-00-00-790-001	Check of the External Leaks of the Hydraulic Components
ASM 291201
AMM 29-12-41-000-002	Removal of the Quantity Indicator of the Blue Hydraulic Reservoir
AMM 29-12-41-000-003	Removal of the Low Level Switch of the Blue Hydraulic Reservoir
AMM 29-12-41-400-002	Installation of the Quantity Indicator of the Blue Hydraulic System
AMM 29-12-41-400-003	Installation of the Low Level Switch of the Blue Hydraulic System
AMM 29-31-00-710-001	Functional Check of Reservoir Low Level Warning
ASM 293101
ASM 293102
ASM 315401
AMM 31-55-34-000-001	Removal of the SDAC
AMM 31-55-34-400-001	Installation of the SDAC
AMM 31-60-00-860-001	EIS Start Procedure

3. Fault Confirmation
Subtask 29-12-00-865-052-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	HYD/HYD PWR/B WARN/& CTL	2702GJ	C12
121VU	HYDRAULIC/LOW/LVL/IND	1832GQ	N32
121VU	HYDRAULIC/HYD/QTY/IND	1831GQ	P35

Subtask 29-12-00-860-052-A

B. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
(3) On the ECAM control panel on the center pedestal, push the HYD pushbutton switch. Make sure that the HYD page is shown on the system display of the ECAM.
(4) Look for fault indications on the upper ECAM DU, the lower ECAM DU and panel 40VU.

4. Fault Isolation
Subtask 29-12-00-810-071-A

A. If the Fault Confirmation gives:

The message HYD B RSVR LO LVL on the upper ECAM DU
The contents indication (shows low-fluid level) on the lower ECAM DU in amber
The BLUE ELEC PUMP P/BSW FAULT on panel 40VU
The single chime and the MASTER CAUT lights come on.

(1) Do a visual check of the quantity shown on the mechanical indicator of the Blue reservoir.
(2) If the quantity shown is more than or equal to 2.4 l (0.6340 USgal):
(a) Do a check for 28 VDC between:

LOW LEVEL SWITCH connector B/A and connector B/C ASM 293102.

(b) If there is no 28 VDC:
1 Do a check of the wiring between:

LOW LEVEL SWITCH connector B/C and CB (1832GQ) and repair the wiring as necessary ASM 293102.

(c) If there is 28VDC:
1 Replace the LOW LEVEL SWITCH AMM 29-12-41-000-003 and AMM 29-12-41-400-003.
(d) If the fault continues:
1 Make sure that the wiring is not connected to GND between:

LOW LEVEL SWITCH connector B/B and DIODE (1156VD) connector 15 ASM 291201 and ASM 293101.

2 If the wiring is connected to GND:

Repair the wiring as necessary.

(e) If the fault continues:

Replace the the QUANTITY INDICATOR - TRANSMITTER AMM 29-12-41-000-002 and AMM 29-12-41-400-002.

(3) If the quantity shown is less than 2.4 l (0.6340 USgal):

Make sure that the drain valve of the hydraulic reservoir has no leaks.

(a) If the drain valve has a leak:

Replace the drain valve.

(b) If the drain valve has no leaks:

Do a check of the hydraulic lines and the components for leaks AMM 29-00-00-790-001 and repair them.

(c) If the fault continues:
1 Do a check of the internal leakage of the Blue hydraulic system AMM 29-00-00-280-002.
2 If the internal leakage rate is too high:

Repair the defective component.

3 If the fault continues, or you can not find a defective component:
a Take a fuel sample from each water drain-valve AMM 12-32-28-281-001.
b Do a check for contamination of the fuel with hydraulic fluid after each removal of a fuel sample.
c If you find hydraulic fluid contamination in one or more fuel samples:

Do a check of the hydraulic lines and components in the applicable tank area for leaks and repair them.

Subtask 29-12-00-810-072-A

B. If the Fault Confirmation gives:

The message HYD B RSVR LO LVL on the upper ECAM DU
The contents indication (shows low fluid level) on the lower ECAM DU in amber.

(1) Do a visual check of the quantity shown on the mechanical indicator of the Blue reservoir.
(2) If the quantity shown is more than or equal to 1.8 l (0.4755 USgal):
(a) Do a check for 26 VAC between:

QUANTITY INDICATOR - TRANSMITTER connector A/D and connector A/E ASM 293101.

1 If there is no 26 VAC:
a Do a check of the wiring between:

QUANTITY INDICATOR - TRANSMITTER connector A/D and CB (1831GQ) and repair the wiring as necessary ASM 293101.

2 If the fault continues:
a Do a check for a ground signal between:

QUANTITY INDICATOR - TRANSMITTER connector A/E and ground ASM 293101.

b If there is no ground signal:

Repair the wiring between QUANTITY INDICATOR - TRANSMITTER connector A/E and ground ASM 293101.

(b) If the fault continues:

Replace the QUANTITY INDICATOR - TRANSMITTER AMM 29-12-41-000-002 and AMM 29-12-41-400-002.

(c) If the fault continues:
1 Do the troubleshooting procedure for the loss of the BLUE RSVR QTY input of the SDAC-1 [1WV1] (Ref. TSM TASK 31-54-00-810-831).
2 If the fault continues:
a Do the troubleshooting procedure for the loss of the BLUE RSVR QTY input of the SDAC-2 [1WV2] (Ref. TSM TASK 31-54-00-810-832).
(3) If the quantity shown is less than or equal to 2.0 l (0.5283 USgal):
(a) Do a check for 28 VDC at:

LOW LEVEL SWITCH connector B/C ASM 293102.

(b) If there is no 28 VDC:
1 Do a check of the wiring between:

LOW LEVEL SWITCH connector B/C and CB (1832GQ) and repair the wiring as necessary ASM 293102.

(c) If there is 28VDC:
1 Replace the LOW LEVEL SWITCH AMM 29-12-41-000-003 and AMM 29-12-41-400-003.
(d) If the fault continues:
1 Make sure that the wiring is not connected to GND between:

LOW LEVEL SWITCH connector B/B and DIODE (1156VD) connector 15 ASM 291201 and ASM 293101.

2 If the wiring is connected to GND:

Repair the wiring as necessary.

(4) Make sure that the drain valve of the hydraulic reservoir has no leaks.
(a) If the drain valve has a leak:

Replace the drain valve.

(b) If the drain valve has no leaks:

Do a check of the hydraulic lines and components for leaks AMM 29-00-00-790-001 and repair them.

Do a check of the internal leakage of the Blue hydraulic system AMM 29-00-00-280-002.

1 If the internal leakage rate is too high:

Repair the defective component.

2 If the fault continues, or you can not find a defective component:
a Take a fuel sample from each water drain-valve AMM 12-32-28-281-001.
b Do a check for contamination of the fuel with hydraulic fluid after each removal of a fuel sample.
c If you find hydraulic fluid contamination in one or more fuel samples:

Do a check of the hydraulic lines and components in the applicable tank area for leaks and repair them.

Subtask 29-12-00-810-054-A

C. If the Fault Confirmation gives:

The message HYD B RSVR LO LVL on the upper ECAM DU
The BLUE ELEC PUMP P/BSW FAULT on panel 40VU
The single chime and the MASTER CAUT lights come on.

(1) Do a visual check of the quantity shown on the mechanical indicator of the Blue reservoir.
(2) If the quantity shown is less than 1.8 l (0.4755 USgal):
(a) Replace the QUANTITY INDICATOR - TRANSMITTER AMM 29-12-41-000-002 and AMM 29-12-41-400-002.
(3) Make sure that the drain valve of the hydraulic reservoir has no leaks.
(a) If the drain valve has a leak:
1 Replace the drain valve.
(b) If the drain valve has no leaks:
1 Do a check of the hydraulic lines and components for leaks AMM 29-00-00-790-001 and repair them.
(c) If the fault continues:
1 Do a check of the internal leakage of the Blue hydraulic system AMM 29-00-00-280-002.
2 If the internal leakage rate is too high:
a Repair the defective component.
3 If the fault continues, or you can not find a defective component:
a Take a fuel sample from each water drain-valve AMM 12-32-28-281-001,
b Do a check for contamination of the fuel with hydraulic fluid after each removal of a fuel sample.
4 If you find hydraulic fluid contamination in one or more fuel samples:
a Do a check of the hydraulic lines and components in the applicable tank area for leaks and repair them.

Subtask 29-12-00-810-065-A

D. If the Fault Confirmation gives:

The message HYD B RSVR LO LVL on the upper ECAM DU
The contents indication (shows normal fluid level) on the lower ECAM DU in green
The BLUE ELEC PUMP P/BSW FAULT on panel 40VU
The single chime and the MASTER CAUT lights come on.

(1) Do a visual check of the quantity shown on the mechanical indicator of the Blue reservoir.
(2) If the quantity shown on the indicator is normal:
(a) Remove the SDAC-1 [1WV1] and SDAC-2 [1WV2] AMM 31-55-34-000-001.
(b) Remove the connector from the LOW LEVEL SWITCH.
(c) Do a check of the wiring for a ground signal between:
1 The LOW LEVEL SWITCH connector B/B and the SDAC-1 [1WV1] SDAC1 connector AA/3E ASM 293101 and ASM 315401.
a If there is a ground signal, repair the wiring.
(d) Install the SDAC-1 [1WV1] and SDAC-2 [1WV2] AMM 31-55-34-400-001.
(e) Install the connector of the LOW LEVEL SWITCH.
(3) If there is no ground signal or the fault continues:

Replace the LOW LEVEL SWITCH AMM 29-12-41-000-003 and AMM 29-12-41-400-003.

Subtask 29-12-00-710-053-A

E. Do the operational test of the fluid low level warning AMM 29-31-00-710-001.

[Rev.8 from Aug 2018] 2026.04.04 04:39:55 UTC