Failure of the Thrust Reverser Isolation Valve (Shut-Off Valve in the open position) on the Engine 1

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1. Possible Causes
· VALVE-THRUST REVERSER HYDRAULIC ISOLATION, ENG1 (50EG1)
· RELAY-THRUST REVERSER LOCKING POWER, ENG1 (2EG1)
· STATIC RELAY-THRUST REVERSER LOCKING CTL, ENG1 (3EG1)
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 78-31-00-710-041 Operational Test of the Thrust Reverser System with the CFDS
Ref. ASM 78-37-01
Ref. AMM 78-37-51-000-010 Removal of the Thrust Reverser Hydraulic Isolation Valve
Ref. AMM 78-37-51-400-010 Installation of the Thrust Reverser Hydraulic Isolation Valve
3. Fault Confirmation
Subtask 78-37-00-865-056-A
A. Table of the circuit breakers used in this procedure:
PANEL DESIGNATION FIN LOCATION
49VU FLIGHT CONTROLS/SEC1/NORM/SPLY 21CE1 B08
105VU FLT CTL/SEC1/STBY SPLY 22CE B01
121VU ENG1/REV/LOCK 1EG1 N44
121VU ENGINE/ENG2/OIL/PRESS/AND REV
SNSR/CHAN A
2EN2 N42
121VU ENGINE/ENG1/OIL/PRESS/AND REV
SNSR/CHAN A
2EN1 N40
121VU FLIGHT CONTROLS/SEC2/SPLY 21CE2 Q18
Subtask 78-37-00-710-062-A
B. Test
(1) Do the operational test of the thrust reverser system (1A and 1B) Ref. AMM 78-31-00-710-041 .
4. Fault Isolation
Subtask 78-37-00-810-056-A
A. If the test gives the maintenance message
ADD REV LK SENS/HC/ 115V 1
(1) Open the circuit breaker 1EG1.
(2) Do the test as given in the Para. 3.
(a) If the reverse opens and the maintenance message ADD REV LK SENS /HC/115V 1 appears:
· replace the VALVE-THRUST REVERSER HYDRAULIC ISOLATION, ENG1 (50EG1) Ref.
AMM 78-37-51-000-010 and Ref. AMM 78-37-51-400-010 .
(b) If the reverse does not open:
· disconnect the connector (50EG1-A) from the thrust reverser hydraulic isolation valve (50EG1)
Ref. ASM 78-37-01.
· on the connector, connect a voltmeter between pin 1 and pin 2.
· open the circuit breakers 2EN1 and 2EN2.
· close the circuit breaker 1EG1.
1 If there is 115VAC:
· replace the RELAY-THRUST REVERSER LOCKING POWER, ENG1 (2EG1) .
2 If there is no 115VAC:
· close the circuit breakers 2EN1 and 2EN2.
· open the circuit breakers 21CE1, 21CE2 and 22CE.
a If there is 115VAC:
· replace the STATIC RELAY-THRUST REVERSER LOCKING CTL, ENG1 (3EG1) .
b If there is no 115VAC:
· refer to the Fault Symptoms List of the Chapter 27.
Subtask 78-37-00-710-063-A
B. Do the test as given in the Para. 3. [Rev.6 from Feb 2017] 2026.04.04 04:38:20 UTC