Failure of the Selector Valve

TASK 32-51-00-810-814-A
Failure of the Selector Valve

1. Possible Causes

steering selector valve
BSCU [10GG]
wiring from the BSCU (10GG) to the servo control (6GC)
wiring from the servo control (6GC) pin A/K to the ground terminal
SEL VALVE/MANIFOLD ASSY [7GC]
wiring from the selector valve (7GC) to the BSCU (10GG)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 12-14-32-614-004	Check NLG Shock Absorber Charge Pressure
AMM 32-42-34-000-001	Removal of the Braking/Steering Control Unit (BSCU)
AMM 32-42-34-400-001	Installation of the Braking/Steering Control Unit (BSCU)
AMM 32-46-00-740-002	BITE Test of the BSCU - Ground Scanning
AMM 32-51-00-720-003	Functional Test of the Nose Wheel Steering with the Handwheel
ASM 325101
AMM 32-51-23-000-001	Removal of the Selector Valve and Manifold-Assembly
AMM 32-51-23-400-001	Installation of the Selector Valve and Manifold-Assembly
AMM 32-51-51-000-003	Removal of the Nose Wheel Steering Electro-Distributor
AMM 32-51-51-400-003	Installation of the Nose Wheel Steering Electro-Distributor

3. Fault Confirmation
Subtask 32-51-00-740-072-A

A. Test
(1) Do the functional test of the Nose Wheel Steering with the handwheel AMM 32-51-00-720-003.
(2) Do the ground scanning of the BSCU AMM 32-46-00-740-002.

4. Fault Isolation
Subtask 32-51-00-810-063-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message STEERING ELECTRO-HYD MODULE 6GC or BSCU:

replace the steering selector valve AMM 32-51-51-000-003 and AMM 32-51-51-400-003.

(1) If the fault continues:

replace the BSCU [10GG] AMM 32-42-34-000-001 and AMM 32-42-34-400-001.

(2) If the fault continues:

do a check for a ground signal at pin A/K of the servo control (6GC) ASM 325101.

(a) If there is a ground signal:

do a check and repair the wiring from the BSCU (10GG) to the servo control (6GC): pin AB/12D to pin A/J ASM 325101.

(b) If there is no ground signal:

do a check and repair the wiring from the servo control (6GC) pin A/K to the ground terminal ASM 325101.

(3) If the fault continues:

do the check of the charge pressure of the nlg shock absorber. AMM 12-14-32-614-004.

Subtask 32-51-00-810-063-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message STEERING ELECTRO-HYD MODULE(6GC)/ BSCU(10GG):

replace the steering selector valve AMM 32-51-51-000-003 and AMM 32-51-51-400-003.

(1) If the fault continues:

replace the BSCU [10GG] AMM 32-42-34-000-001 and AMM 32-42-34-400-001.

(2) If the fault continues:

do a check for a ground signal at pin A/K of the servo control (6GC) ASM 325101.

(a) If there is a ground signal:

do a check and repair the wiring from the BSCU (10GG) to the servo control (6GC): pin AB/12D to pin A/J ASM 325101.

(b) If there is no ground signal:

do a check and repair the wiring from the servo control (6GC) pin A/K to the ground terminal ASM 325101.

(3) If the fault continues:

do the check of the charge pressure of the nose landing gear shock absorber AMM 12-14-32-614-004.

Subtask 32-51-00-810-063-C ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message STEERING SELECTOR VALVE(7GC)/ BSCU(10GG):

replace the SEL VALVE/MANIFOLD ASSY [7GC] AMM 32-51-23-000-001 and AMM 32-51-23-400-001.

(1) If the fault continues:

replace the BSCU [10GG] AMM 32-42-34-000-001 and AMM 32-42-34-400-001.

(2) If the fault continues:

do a check and repair the wiring from the selector valve (7GC) to the BSCU (10GG).

(3) If the fault continues:

do the check of the charge pressure of the nose landing gear shock absorber AMM 12-14-32-614-004.

Subtask 32-51-00-740-073-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:31:48 UTC