49-11-01
ALL ú ú 04 Page 424 ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
S 424-112
(2)
Install the V-band clamp (7) that connects the APU to the exhaust duct (Fig. 404):
(a)
Put the V-band clamp (7) on the exhaust duct.
(b)
Close the V-band clamp (7).
(c)
Tighten the V-band clamp (7) to 45-55 pound-inches (5.1-6.2 newton-meters).
(d)
Lightly tap the edge of the V-band clamp (7) with a rubber mallet.
(e)
Continue to tighten and tap the V-band clamp (7) until the torque value stays constant.
S 084-113
(3)
Loosen the turnbuckle and remove the support strap from the APU exhaust duct and keyhole slot bracket (Fig. 401).
S 424-117
(4)
Connect the APU ducts (Fig. 404):
(a)
Install a new seal (3) in the groove of the pneumatic bleed duct (2).
(b)
Connect the pneumatic bleed duct (2) to the supply duct (5).
(c)
Install the coupling clamp (4) on the pneumatic bleed duct (2) and supply duct (5). 1) Tighten the coupling clamp (4) to 50 pound-inches (5.7
newton-meters).
S 424-118
(5)
Connect the APU fuel and drain lines to the drain bracket (Fig. 405):
(a)
Remove the protection covers from the drain lines (14), (15), (16), (17) and fittings on the drain bracket.
(b)
Remove the flareless tube plug from the fuel inlet line (18).
CAUTION: DO NOT TWIST THE FUEL INLET LINE WHEN YOU TIGHTEN THE FUEL
_______ INLET LINE. MAKE SURE THAT YOU HOLD THE FUEL FITTING BEHIND THE DRAIN BRACKET WITH THE WRENCH TO PREVENT DAMAGE TO THE FUEL INLET LINE. A DAMAGE OR TWISTED FUEL INLET LINE CAN CAUSE NOT SUFFICIENT FUEL TO THE APU.
CAUTION: MAKE SURE THERE IS A STRAIGHT FITTING INSTALLED ON THE END
_______ OF THE FUEL INLET LINE AT THE DRAIN BRACKET. IF THERE IS A 45 DEGREE FITTING, THE POWER CABLES FOR THE RIGHT APU GENERATOR CAN WEAR ON THE FUEL INLET LINE. THIS CAN CAUSE DAMAGE TO THE POWER CABLES FOR THE RIGHT APU GENERATOR.
(c) Connect the fuel inlet line (18) to the fuel fitting on the drain bracket. 1) Tighten the fuel inlet line (18) to 855-945 pound-inches
(96.6-106.8 newton-meters).
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49-11-01
ALL ú ú 05 Page 425 ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
(d)
Tighten the fuel inlet line (18) at the bulkhead to 855-945 pound-inches (96.6-106.8 newton-meters).
(e)
Make sure there is a minimum clearance of 0.5 inch (12.7 mm) between the fuel inlet line (18, Fig. 405) and generator duct (6, Fig. 404). 1) If the minimum clearance is less than 0.5 inch (12.7 mm),
adjust the generator duct (6, Fig. 404).
(f)
Connect the drain lines (14), (15), (16), (17) to the fittings on the drain bracket.
S 424-119
(6)
Connect the APU electrical connections (Fig. 405):
(a)
Remove the caps from these items: 1) The two APU control cables DM299A (24) and DM299B (23). 2) The two APU control connectors (25). 3) The two control cables DG2A (11) and DG2B (10) for the
generator No. 1 (9). 4) The two control cables DG3A (8) and DG3B (6) for the generator No. 2 (7).
(b)
Remove the two bolts (27), four washers (26) and two nuts (28) from the harness support bracket.
(c)
Connect the two APU control cables DM299A (24) and DM299B (23) to the two APU control connectors (25).
(d)
Install the two bolts (27), four washers (26) and two nuts (28) that attach the two clamps and two APU control cables DM299B (23) and DM299A (24) to the harness support bracket.
(e)
Connect the two control cables DG2A (11) and DG2B (10) to generator No. 1 (9).
(f)
Connect the two control cables DG3A (8) and DG3B (6) to generator No. 2 (7).
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