Failure of the Two Hydraulic Pipes (Green System) on the Same Landing Gear (Normal Brake System Inoperative)

TASK 32-42-00-810-849-A
Failure of the Two Hydraulic Pipes (Green System) on the Same Landing Gear (Normal Brake System Inoperative)

1. Possible Causes

Green system hydraulic pipes
wiring between the BSCU (10GG) and the brake selector valve (23GG)
SEL VALVE-BRK [23GG]
PRESS XDCR-NORM BRK WHEEL 1 [11GG]
PRESS XDCR-NORM BRK WHEEL 2 [13GG]
PRESS XDCR-NORM BRK WHEEL 3 [12GG]
PRESS XDCR-NORM BRK WHEEL 4 [14GG]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 29-23-00-863-001	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
AMM 31-32-00-860-009	Procedure to Get Access to the SYSTEM REPORT/TEST/L/G Page
AMM 32-42-00-870-001	Bleeding of the Normal Braking at the Brake Units
ASM 324201
AMM 32-42-21-000-001	Removal of the Normal-Brake Pressure Transducer
AMM 32-42-21-400-001	Installation of the Normal-Brake Pressure Transducer
AMM 32-42-36-860-001	Reactivation of the Normal-Brake Safety-Valve

3. Fault Confirmation
Subtask 32-42-00-710-058-A

A. Test
(1) Do a check for leaks or rupture on the hydraulic pipes related to the Green system on a same landing gear.

4. Fault Isolation
Subtask 32-42-00-810-106-C

A. If you find leaks or rupture:

replace the Green system hydraulic pipes
reactivate the related brake safety valves AMM 32-42-36-860-001
bleed the Normal brake system at the brake unit AMM 32-42-00-870-001.

(1) If you do not find leaks or ruptures:

check the wiring between the BSCU (10GG) and the brake selector valve (23GG) ASM 324201.

(a) if the wiring is correct

replace the SEL VALVE-BRK [23GG] .

(b) if the wiring is not correct

repair the wiring.

(2) If the fault continues:
(a) On the MCDU, do a check of the class 3 fault report.
(b) if the class 3 fault report gives a maintenance message related to the braking system:

Do the related trouble shooting procedure.

(3) if there is no class 3 fault message:
(a) On the panel 110VU, make sure that the PARK BRK control switch is in the OFF position.
(b) On the panel 402VU, make sure that the A/SKID & N/W STRG switch is at ON.
(c) Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the electric pump AMM 29-23-00-863-001.
(d) On the captain or the first officer side, Fully press the two brake pedals.
(e) On the MCDU, get the SYSTEM REPORT/TEST/L/G page AMM 31-32-00-860-009.
(f) On the SYSTEM REPORT/TEST/L/G page, push the line key adjacent to the BSCU CHAN/SYS 1/2 indication.
(g) On the BSCU CHAN/SYS 1(2) page, push the line key adjacent to the SPECIFIC DATA indication.
(h) On the BSCU CHAN/SYS 1(2)/SPECIFIC DATA page, push the line adjacent to the SYSTEM DATA page.
(i) Push the line key adjacent to the REFRESH indication.
(4) Do a check of the Normal brake servovalves pressure transducers values 11GG/13GG and 12GG/14GG.
(a) If the Normal brake servovalve pressure-transducers values 11GG and 13GG are not equal to 175 +10 bar or -10 bar (2538.1598 +145.0377 psi or -145.0377 psi):

Replace the PRESS XDCR-NORM BRK WHEEL 1 [11GG] and PRESS XDCR-NORM BRK WHEEL 2 [13GG] AMM 32-42-21-000-001 AMM 32-42-21-400-001.

(b) If the Normal brake servovalve pressure-transducers values 12GG and 14GG are not equal to 175 +10 bar or -10 bar (2538.1598 +145.0377 psi or -145.0377 psi):

Replace the PRESS XDCR-NORM BRK WHEEL 3 [12GG] and PRESS XDCR-NORM BRK WHEEL 4 [14GG] AMM 32-42-21-000-001 AMM 32-42-21-400-001.

[Rev.8 from Aug 2018] 2026.04.04 04:31:34 UTC