R HYD SOV FAIL
(Caution)

• DAU 1 is sensing the right hydraulic Shut-off Valve (SOV) open, and the DAU 4 is reporting the right fire handle out and/or the RH hydraulic SOV switch selected to CLOSE.
OR
• DAU 1 is sensing the right hydraulic SOV closed, and the DAU 4 is reporting the right fire handle pushed in and/or the RH hydraulic SOV switch selected to OPEN.

• Right Hydraulic SOV
• Data Acquisition Unit (DAU) 1 (A17)
• Data Acquisition Unit (DAU) 4
• R Engine Firewall Shut-off Valve (EDP 2A) (L46)
• Fire-Handle-Switch
• RH SOV Cockpit Switch
• Junction Box 4 (JB 4), (mother board, or PCB 2 card, or K20 Relay)
• DC Power Center (DCPC) (A63)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Notice To Operators (NTO): None

Flight Operation Notifications Manual (FONM): None

• When replacing the pressure filters, a hydraulic lock has been known to prevent new filter installation. A "B" nut next to the filter manifold may need to be loosened or removed to bleed off pressure and allow the installation of the filter.
• Using the CMM for the Hyd. SOV, it is possible to change the actuator of the valve without removing the hydraulic Valve. There may be internal seals in the valve portion that are preventing the valve to move freely, and has caused the actuator to fail.
• Do not move the valve indicator.
• You can use the test points on the JB boxes to verify the relay, or card integrity.
• Use the ground or power side of the relay coil to ensure the relay is functional. The relay is on the PCB card. The relay can be changed per the JB CMM.

1. Ensure fire handle is in, and power is off the affected system, or aircraft.
2. In the aft equipment bay, remove connector L46P1 at the RH Hyd. SOV and inspect the pins and sockets for damage or corrosion. Leave connector off.
3. CAUTION: Do not use the visual indicator to manually operate the valve. Damage to the indicator or valve may occur.
4. Install connector L46P1 on to RH Hyd. SOV.
5. Have an assistant do an operational test of the right hydraulic SOV, while you monitor the valve in the back. If no movement is seen on the valve when commanded, and the valve moves when you assist the indicator arm; ensure the EICAS Hyd. Page indications are accurate to the valve position and commands. Remember that CAIMS/ System Diagnostic/ ATA 31/ DAU 1A, and 1B/ LRU Test/ Discreet Inputs allows you to see DAU input from the RH Hyd. SOV.
6. If system checks are good, do close out. If fault remains continue with next step.
7. If the circuit breaker does not trip, go to step 10.
8. If the circuit breaker trips:

   • Disconnect the right hydraulic SOV connector L46P1.
   • Reset the right hydraulic SOV circuit breaker.
   • If the circuit breaker does not trip, replace the right hydraulic SOV.
   • If the circuit breaker trips, disconnect JB4 connector JB4EP1.
   • If the circuit breaker does not trip, do a wiring check from right hydraulic SOV to JB4 and replace the JB4 (Remember if you want to change the PCB 2 Card, that your fault could be in the back of the JB4 motherboard, and the card will not fix the problem).
   • If the circuit breaker trips, do a wiring check from JB4 to DCPC.

9. If the right hydraulic SOV moves to the close position, go to step 12.
10. If the right hydraulic SOV does not move to the close position:

    1. Disconnect the right hydraulic SOV connector L46P1, verify good ground at pin H.
    2. Do a voltage check between L46P1-G (+) to L46P1-H (-).
    3. If 28 volt is present, replace the right hydraulic SOV.
    4. If the voltage is not present, remove the JB4 face plate and check for 28 volts at PCB 2 TP-60.
    5. If the voltage is not good, go to step 11.g).
    6. If the voltage is good, do a wiring check between JB 4 and the right hydraulic SOV connector L46P1 and repair applicable wiring.
    7. Remove the JB4 face plate and check for 28 volts at PCB 2 TP-28.
    8. If the voltage is not good, do a wiring check of wiring between JB4 and DCPC, if wiring is good, replace DCPC.
    9. If the voltage is good, disconnect JB4 connector JB4EP1 and check for:

       • Ground at JB4EP1-15 with the RH hydraulic SOV control switch IN.
       • Open at JB4EP1-15 with the RH hydraulic SOV control switch OUT.
       • Ground at JB4EP1-16 with engine No.2 fire handle pulled.
       • Open at JB4EP1-16 with engine No.2 fire handle pushed in.

       If any of the above readings are not good do a wiring check between the JB4 and the applicable panel and replace the applicable panel if required.

    10. Verify for continuity between JB4 connector JB4EP1-2 and JB4EP1-17.
    If there is no continuity, repair wire.
    11. If all of the above are good, replace the JB4. (Remember if you want to change the PCB 2 Card, that your fault could be in the back of the JB4 motherboard, and the card will not fix the problem).

11. If the right hydraulic SOV moves to the open position, go to step 14.
12. If the right hydraulic SOV does not move to the open position:

    1. Disconnect the right hydraulic SOV connector L46P1, verify good ground at pin H.
    2. Do a voltage check between L46P1-A (+) to L46P1-H (-).
    3. If 28 volt is present, replace the right hydraulic SOV.
    4. If the voltage is not present, remove the JB4 face plate and check for 28 volts at PCB 2 TP-61.
    5. If the voltage is not good, go to step 12. G.).
    6. If the voltage is good, do a wiring check between JB 4 and the right hydraulic SOV connector L46P1 and repair applicable wiring.
    7. Remove the JB4 face plate and check for 28 volts at PCB 2 TP-28.
    8. If the voltage is not good, do a wiring check of wiring between JB4 and DCPC, if wiring is good, replace DCPC.
    9. If the voltage is good, disconnect JB4 connector JB4EP1 and check for:

       • Ground at JB4EP1-15 with the RH hydraulic SOV control switch IN.
       • Open at JB4EP1-15 with the RH hydraulic SOV control switch OUT.
       • Ground at JB4EP1-16 with engine No. 2 fire handle pulled.
       • Open at JB4EP1-16 with engine No. 2 fire handle pushed in.

    If any of the above readings are not good, do a wiring check between the JB3 and the applicable panel and replace the applicable panel if required.
    10. Verify for continuity between JB4 connector JB4EP1-2 and JB4EP1-17. If there is no continuity, repair wire.
    11. If all of the above are good, replace the JB4. (Remember if you want to change the PCB 2 Card, that your fault could be in the back of the JB4 motherboard, and the card will not fix the problem).

13. Set the right engine fire handle IN and the RH hydraulic SOV switch OUT (open).
14. Disconnect the right hydraulic SOV connector L46P1 and install a jumper between L46P1- C and H.
15. If the R HYD SOV FAIL message goes away, replace the SOV.
16. If the R HYD SOV FAIL message is still shown, remove jumper and connect L46P1.
17. Interchange DAU 1 with another DAU.
18. Remove DAU 1 and check for the following readings:

    • Ground at DAU 1 connector A17AP1-C6.
    • Open at DAU 1 connector A17AP1-C13.

If any of the above readings are not good, do a wiring check between the right hydraulic SOV and the DAU 1.
19. If the above readings are good, select the right hydraulic SOV switch IN (close).
20. Check for the following readings:

    • Open at DAU 1 connector A17AP1-C9.
    • Ground at DAU 1 connector A17AP1-C15.

    If any of the above readings are not good, do a wiring check between the right hydraulic SOV and the DAU 1.

21. If the above readings are good, install the DAU 1.
22. Disconnect the right hydraulic SOV connector L46P1 and install a jumper between L46P1- E and H.
23. If the R HYD SOV FAIL message is still shown, replace the DAU 1.
24. Remove jumper and connect L46P1.
25. Do close out.