FWD  SEE  A  SEE  B  A  SEE  C  FWD 
APU COMPARTMENT  LOAD GEARBOX PORT 
GEARBOX PORT ACCESSORY 

1. PACKING 
1. PACKING 
DETECTOR 2. CHIP DETECTOR 2. CHIP 
4. PACKING 5. PACKING 
B FWD PLUG 3. MAGNETIC 4. PACKING 5. PACKING  FWD  C  PLUG 3. MAGNETIC 

Chip Detector Inspection
Figure 601

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
 49-27-04
 ALL  ú ú 03 Page 604 ú Feb 18/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
F58300
 (c)

A
747-400 MAINTENANCE MANUAL
 5)  Install the two magnetic plugs (3) in the two chip detectors (2).
 NOTE:____ Push in and turn the two magnetic plugs (3) 90°
 until the two locking tabs engage the valve body of
 the two chip detectors (2).  The red lines and
 grooves of the magnetic plug and valve body must be
 aligned together.
 6)  Replace the oil filter element (AMM 49-27-03/401).
 NOTE:____ During the oil filter element installation test,
 make sure you operate the APU for a minimum of 15
 minutes before you do the APU usual shutdown.
 7)  Remove the two magnetic plugs (3) from the two chip
 detectors (2).
 NOTE:____ Push in and turn to unlock the two magnetic plugs
 (3) for the removal.
 8)  Remove the four packings (4), (5) from the two magnetic
 plugs (3) and two chip detectors (2).
 a)  Discard the four packings (4), (5).
 9)  Visually examine the two magnetic plugs (3) for metal
 particles.

 10) If you find more metal particles on the two magnetic plugs
 (3), replace the APU (AMM 49-11-01/401).If you do not find metal particles on the two magnetic plugs (3), visually examine the two valve bodies of the two chip detectors (2) for leakage: 1) Clean the two valve bodies of the two chip detectors (2)
 with alcohol and a cloth. 2) Use the air source to dry the two valve bodies of the two chip detectors (2).
 NOTE: It is recommended that you use a pressure of 30-60
____ psig (207-414 kPa) of air or nitrogen to dry the two valve bodies of the two chip detectors.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
 49-27-04
 ALL  ú ú 03 Page 605 ú Feb 18/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
 3)
4)

A
747-400
MAINTENANCE MANUAL

Visually examine the two valve bodies for oil leakage.If you find oil leakage on the two valve bodies, do these steps:
 a)  Do this task: Drain the APU Oil (AMM 12-22-02/301).
 b)  Remove the applicable chip detector(s) (2) from the
 accessory or load gearbox port.
 c)  Remove and discard the packing(s) (1).
 d)  Lubricate the new packing(s) (1) with a light coat of
 oil.
 e)  Install the packing(s) (1) on the valve body of the
 chip detector(s) (2).
 f)  Install the chip detector(s) (2) in the accessory or
 load gearbox port.
 g)  Tighten the chip detector(s) (2) to 40-50 inch-pounds
 (4.5-5.7 newton-meters).
 h)  Install the lockwire on the valve body of the chip
 detector(s).
 i)  Make sure the two magnetic plugs (3) are clean. If the
 magnetic plugs are not clean, clean the plugs with
 alcohol and a cloth.
 j)  Make sure the two magnetic plugs (3) can each lift an
 eight ounce (0.23 kilogram) (minimum) ferromagnetic
 steel weight.
 k)  If the two magnetic plugs (3) cannot lift the weight,
 replace the magnetic plug(s).
 l)  Lubricate the four new packings (4), (5) with a light
 coat of oil.
 m)  Install the two packings (4) on the two magnetic plugs
 (3) and two packings (5) on the two chip detectors (2).
 n)  Install the two magnetic plugs (3) in the two chip
 detectors (2).
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 機載輔助動力 2(18)