............................................................................... | COVER | OD | 10.876 | 10.878 | | | | | | (276.251) | (276.301) | 0.002 | 0.008 | ...................................................... (0.051) | (0.202) | | TURBINE | ID | 10.880 | 10.884 | | | | EXHAUST | | (276.352) | (276.453) | | | | CASE | | | | | | 2.................…......….............….............…...........…............1
(b)
Fully lubricate the new packing with engine oil.
(c)
Install the new packing in the groove in the rear flange of the cover.
(d)
Install 8 to 10 work bolts equally spaced around the cover.
(e)
Tighten the bolts equally in small increments to pull the cover into position equally.
(f)
Monitor the engagement of the cover to make sure the packing is not cut.
(g)
Tighten the work bolts to 85-95 inch-pounds
(9.6 - 10.7 Newton meter) after the cover is fully seated.
S 784-042-N00
(2)
Leak check the No. 4 bearing cover, the No. 4 bearing oil pressure tube, the No. 4 bearing oil scavenge tube and the bearing cover mating flanges.
(a)
Install a cap on the outboard end of the oil pressure tube.
(b)
Apply 18.0 - 20.0 psig (124.1 - 137.9 kPacals) air pressure to the outboard end of the scavenge tube.
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(c) Apply leak check fluid to: 1) The tube connections on the inboard end of the the pressure
tube. 2) The inboard end of the oil scavenge tube. 3) The empty bolt holes in the bearing cover. 4) All around the bearing cover to exhaust case mating
flanges.
(d)
No leaks are permitted.
1) If leaks are found, disassemble and correct the cause of
the leaks.
2) If no leaks are found, continue assembly.
(e)
Remove the 8 to 10 work bolts.
S 424-039-N00
(3)
Do the steps that follow to install the No. 4 bearing heat shield:
(a)
Put the No. 4 bearing heat shield in the recess of the No. 4
bearing shield.
1) Align the boltholes.
(b)
Install the No. 4 bearing shield over the No. 4 bearing cover installed at the rear inner flange of the turbine exhaust case.
NOTE: For engines POST-PW-SB 79-76, it will be necessary to
____ angle the cover and heat shield to clear the No. 4 bearing oil pressure tube.
(c)
Lubricate the 30 bolts with engine oil.
(d)
Attach the shield with the 30 bolts.
(e)
Tighten the bolts to 85-95 pound-inches (9.604-10.734
newton-meters)
S 424-043-N00
(4) Complete the installation of the No. 4 bearing oil scavenge tube and the No. 4 oil pressure tube as follows:
CAUTION: HOLD THE SCAVENGE TUBE (REAR) AT THE WRENCHING FLATS WHEN
_______ YOU THIGHTEN THE TUBE NUT. IF YOU DO NOT DO THIS YOU CAN CAUSE DAMAGE TO THE TUBE ASSEMBLY.
(a)
Connect the nut to the No. 4 bearing scavenge tube (rear).
1) Lubricate the threads with antigalling compound.
(b)
Tighten the nut to 200-225 inch-pounds
(22.6-25.4 Newton-meters).
(c)
Install lockwire (AMM 70-21-00/201).
S 424-044-N00
(5)
Position the No. 4 bearing scavenge heat shields around the inboard end of the tube.
(a)
Install lockwire through the eyelets in the heat shields
(AMM 70-21-00/201).
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////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
CAUTION:_______ HOLD THE PRESSURE TUBE (UPPER) AT THE WRENCHING FLATS WHEN YOU THIGHTEN THE TUBE NUT. IF YOU DO NOT DO THIS YOU CAN CAUSE DAMAGE TO THE TUBE ASSEMBLY.
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本文链接地址：747-400 AMM 飞机维护手册 发动机 ENGINE 2(117)
