S 014-046
(5)
Open the left fan cowl panel (Ref 71-11-04/201).
S 014-047
(6)
Open the left core cowl panel (Ref 71-11-06/201).
S 014-048
WARNING: OBEY THE INSTRUCTIONS IN THE PROCEDURE TO OPEN THE THRUST
_______ REVERSERS. IF YOU DO NOT OBEY THE INSTRUCTIONS WHEN YOU OPEN THE THRUST REVERSERS, INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR.
(7) Open the left thrust reverser (Ref 78-31-00/201).
S 864-006
WARNING: YOU MUST RELEASE THE PRESSURE IN THE PNEUMATIC DUCT BEFORE
_______ YOU REMOVE A PNEUMATIC SYSTEM COMPONENT. THE HOT, HIGH PRESSURE AIR CAN CAUSE INJURIES TO PERSONS.
(8)
Do the steps that follow to release the pressure in the duct between the PRV and the HPSOV (Ref 36-11-05/201).
(a)
Turn the manual override drive on the HPSOV to the OPEN position momentarily.
(b)
Put the manual override drive to the CLOSED position.
S 024-065
(9)
Do these steps to remove the P-Clamps:
(a)
Remove the nut and washer that hold the P-Clamp to the valve actuator.
NOTE: Keep the nut and the washer for the installation.
____
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(b) Remove the P-Clamp and the spacers from the valve actuator.
NOTE:____ Keep the P-Clamp on the wires for the installation.
Keep the spacers for the installation.
(c) Remove and discard the lockwire from the bolt that holds the
P-Clamp to the valve heat shield (AMM 20-11-28/401).
(d) Remove the bolt and the washer that hold the P-Clamp to the
valve heat shield.
NOTE:____ Valve PNs 790270-1 through -12 have a long bolt that
goes through a spacer under the heat shield. Hold the
spacer while you remove the bolt to prevent dislocating
the spacer. Newer valves have a short bolt that screws
into a threaded spacer under the heat shield.
(e) Remove the P-Clamp from the valve heat shield.
NOTE:____ Keep the P-Clamp on the wires for the installation.
(f) Reinstall the washer and the bolt on the valve heat shield.
S 034-007
(10)
Disconnect the wires from the PRV (1) terminal block.
(a)
Put a tag on the wires and the terminals to make the installation of the PRV easier.
S 024-066
(11) Remove the nut, the bolt, and the washers that hold the bonding jumper to the valve.
NOTE: Keep the bolt, the nut and the washers for the installation.
____
S 034-008
(12)
Disconnect the actuator pressure tube from the PRV (1).
(a)
Put the protective caps on the open tube and the port to keep out unwanted objects.
S 034-039
(13)
Disconnect the couplings (7) upstream and downstream of the PRV (1).
S 024-040
(14)
Remove the PRV (1).
(a)
If you cannot easily remove the PRV because it is too tight, loosen one of the duct sections on either side of the PRV (AMM 36-11-01/401).
S 034-010
(15)
Remove the seals (8) from the duct flanges.
(a)
Examine the seals for damage.
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(b) Replace the seals that have damage.
S 034-011
(16)
Put the protective covers on the open ducts to keep out unwanted objects.
S 034-012
(17)
Do the steps that follow if you must install a new PRV (1):
(a)
Remove the fittings from the PRV.
(b) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 气动系统 PNEUMATIC SYSTEM(119)
