BLEED AIR VALVE - REMOVAL/INSTALLATION
1. Equipment and Materials
A. Antiseize Compound - Fel-Pro C-5A (AMM 20-30-21/201)
2. Prepare Bleed Air Valve for Removal
A. Position BATTERY SWITCH and APU MASTER SWITCH to OFF and placard that APU maintenance is "in work."
B. Open the circuit breaker on M280 module-APU accessory unit on E3-3 electronic shelf.
C. Open stabilizer trim control circuit breaker on P6 panel and placard that APU maintenance is "in-work".
D. Open access door 3701, just forward of APU compartment.
E. Open APU compartment access door latches and open access door.
3. Remove Bleed Air Valve (Fig. 401)
A. Enter horizontal stabilizer jackscrew compartment, and at station 1075 (approximately), remove clamp from APU bleed air duct.
B. In APU compartment, on aft side of APU compartment firewall, remove bolt, washer, and nut securing turnbuckle to bleed air duct.
C. Disconnect electrical connectors from bleed air valve.
D. Disconnect bleed load control air line from valve.
E. Disconnect and remove clamps securing bleed air valve to duct.
F. Remove bleed air valve and seal.
4. Install Bleed Air Valve (Fig. 401)
A. Install seal in recess in upstream flange of bleed air valve.
B. Install bleed air valve between duct flanges.
C. Coat threads of clamp bolts with antiseize compound. Install clamps securing valve to flanges, but do not tighten.
D. Connect bleed load control air line to valve. Rotate valve if necessary to facilitate connection.
E. Position and secure turnbuckle to hanger clamp on APU bleed air duct with bolt, washer, and nut. Do not tighten at this time.
F. Enter horizontal stabilizer jackscrew compartment and install clamp securing sections of APU bleed air duct. Torque clamp coupling nut to approximately 50 pound-inches.
G. In APU compartment, tighten bleed air valve clamp coupling nuts and hanger clamp nut to approximately 50 pound-inches of torque.
H. Connect electrical plugs to valve and safety wire.
I. Close the circuit breaker on M280 module-APU accessory unit on E3-3 electronic shelf.
J. Do the APU operation test - LOADED CONDITION (AMM 49-11-0/501).
(1)
During the APU operation, examine the clamp joints for leakage.
(2)
If you found leakage, repair the cause of it.
5. Restore Airplane to Normal Configuration
A. Close and latch APU compartment access door.
B. Close and latch access door 3701 just forward of APU compartment.
C. Open stabilizer trim circuit breaker on P6 panel and remove placard.
D. Remove placards and position BATTERY SWITCH to OFF if electrical power is no longer required.
502
Feb 20/94 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 49-52-11 Page 401
Bleed Air Valve Installation 502
49-52-11Page 402 Figure 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Feb 20/86
BLEED AIR DUCT - REMOVAL/INSTALLATION
1. General
A. The bleed air duct is found in the APU compartment between the upper shroud and the bleed air valve.
2. Bleed Air Duct Removal (Fig. 401)
A. Remove the Bleed Air Duct
(1)
Remove the upper shroud (AMM 49-12-31/401).
NOTE: The bleed air duct is disconnected from the upper shroud and the bleed air valve during the upper shroud removal.
(2)
Disconnect the pressure line for the pneumatic actuator from the reducer.
(3)
Remove the bleed air line:
(a)
Disconnect the bleed air line from the check valve for the fuel sensing flow control.
(b)
Remove the bleed air line.
(4)
Carefully remove the bleed air duct from the APU compartment.
(5)
If the bleed air duct will be replaced, remove these parts:
(a)
Remove the pneumatic line filter for the cooling air shutoff valve (AMM 49-51-22/401).
(b)
Remove the check valve for the fuel sensing flow control (AMM 49-31-93/401).
3. Bleed Air Duct Installation (Fig. 401)
A. Install the Bleed Air Duct
(1) If a new bleed air duct will be installed, install these parts:
(a)
Install the check valve for the fuel sensing flow control (AMM 49-31-93/401).
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