Failure of the BRK ALTN Selector Valve

TASK 32-43-00-810-821-A
Failure of the BRK ALTN Selector Valve

1. Possible Causes

SEL VALVE-ALTN BRK [99GG]
ABCU [95GG]
wiring.

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 32-43-00-710-002	Operational Check to start the Functional Test of the Alternate Braking Automatically (flight simulated)
ASM 324303
AMM 32-43-34-000-001	Removal of the Alternate Braking Control Unit (ABCU)
AMM 32-43-34-400-001	Installation of the Alternate Braking Control Unit (ABCU)
AMM 32-43-51-000-001	Removal of the Alternate Braking Selector Valve
AMM 32-43-51-400-001	Installation of the Alternate Braking Selector Valve
TSM TASK 32-42-00-03	NORMAL BRAKING - TASK SUPPORTING DATA

3. Fault Confirmation
Subtask 32-43-00-740-060-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational check to start the functional test of the Alternate Braking automatically (flight simulated) AMM 32-43-00-710-002.
(2) Read the TROUBLE SHOOTING DATA of the BSCU on the MCDU 32-42-00-03 TSM TASK 32-42-00-03.
(3) Print the TROUBLE SHOOTING DATA of the BSCU .

4. Fault Isolation
Subtask 32-43-00-810-070-A ** ON A/C NOT FOR ALL

A. If the operational check gives the maintenance message BRK ALTN SELECTOR VALVE(99GG) and the TROUBLE SHOOTING DATA gives the fault code 1590:
(1) Do a check of the Alternate Pressure Transducer Left (APTL) and Alternate Pressure Transducer Right (APTR) pressure values 32-42-00-03 TSM TASK 32-42-00-03 printed in step 3.A.(3).
(2) If one of these pressure values is more than 30 bar (435.1131 psi):

Replace the SEL VALVE-ALTN BRK [99GG] AMM 32-43-51-000-001 AMM 32-43-51-400-001.

(3) If the fault continues:

Replace the ABCU [95GG] AMM 32-43-34-000-001 AMM 32-43-34-400-001.

(4) If the fault continues:

Do a check and repair the wiring. between the ABCU and the SEL VALVE-ALTN BRK ASM 324303

Subtask 32-43-00-740-061-A ** ON A/C NOT FOR ALL

B. Do the test given in Para.3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:31:41 UTC