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时间:2011-03-31 15:25来源:蓝天飞行翻译 作者:航空
曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

1. General
A.  Trouble shooting the oil filter bypass warning system is a comparatively simple operation since few malfunctions can occur. Symptoms of system defects will be indicated by noting the operation of the warning light are limited to the following: illumination of the light at differential pressures below 38 psi, illumination of the light at the wrong pressures, and the failure of the light to illuminate. The following chart cover the trouble shooting procedures.
NOTE:  For starting and ground operation of JT8D engines incorporating the 15 or 40 microns main oil filter: Illumination of the differential oil pressure warning light may be caused by contaminant material in the filter, by cold, viscous oil, or by a combination of the two. In general, when oil temperature is above 25°C (77°F) at idle, illumination of the warning light indicates the presence of contaminants alone and the filter should be serviced immediately. If oil temperature is 25°C or below, the warning light may remain on after start, but should go out as the oil warms. Normally the oil will warm sufficiently within 5 minutes to extinguish the warning light.

500 
Feb 20/90  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  79-35-0 Page 101 


OIL FILTER BYPASS WARNING SYSTEM -ADJUSTMENT/TEST
1.  Oil Filter Bypass Warning System Test
A.  General
(1)  Since the oil filter bypass switch actuates only when the oil filter is clogged, it is only practical to test this switch using an external air pressure source.
B.  Equipment and Materials
(1)  
Variable air pressure source - 38 psig minimum pressure

(2) 
 Engine oil


C.  Prepare to Test Oil Filter Bypass Warning System
(1)  
Open left cowl panel.

(2)  
Connect external electrical power to airplane.


D.  Test Oil Filter Bypass Warning System
(1)  
Close Sec 2 and Sec 5 circuit breakers on P6 panel.

(2)  
Observe oil filter bypass warning light on engine instrument panel. Light should be out.

(3)  
Disconnect oil filter inlet pressure sensing line at oil filter bypass switch OIL port and connect air pressure source to switch. (See figure 501.)

(4)  
Gradually apply air pressure to oil filter bypass switch. Filter bypass warning light should illuminate when pressure reaches 34 psig.

CAUTION:  DO NOT OVERPRESSURIZE OIL FILTER BYPASS SWITCH OR DAMAGE TO UNIT MAY OCCUR.

(5)
Hold pressure and open Sec 2 and Sec 5 circuit breakers. Light should go out.


500 
Aug 15/67  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  79-35-0 Page 501 


H27815
Oil Filter Bypass Warning System Test  551 
79-35-0  Figure 501  Oct 20/86 
Page 502 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 


(6)  
Gradually reduce pressure to zero psig.

(7)  
Close, and then open Sec 2 and Sec 5 circuit breakers on panel P6. Light should remain out.

(8)  
Remove air pressure source from oil filter bypass switch.

(9)  
Loosely connect oil filter inlet sensing line to oil filter bypass switch pressure port. Motor or operate engine until oil leakage is observed at fitting. Tighten fitting and lockwire.


E.  Restore Airplane to Normal Configuration
(1)  
Close engine cowl panel.

(2)  
Close Sec 2 and Sec 5 circuit breakers on panel P6.

(3)  
If no longer required, remove external electrical power.


5B3 
Feb 20/84  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  79-35-0 Page 503 


OIL FILTER BYPASS SWITCH - REMOVAL/INSTALLATION
1.  Prepare to Remove Oil Filter Bypass Switch
A.  Open left cowl panel.
B.  Open Sec 2 and 5 circuit breakers on circuit breaker panel P6.
2.  Remove Oil Filter Bypass Switch (Fig. 401)
A.  Remove electrical connector from oil filter bypass switch.
B.  Disconnect tubing between filter inlet port and switch at reducer union in switch OIL port. On some engines a flexible hose is installed.
C.  Disconnect tubing between filter outlet port and switch at reducer union in switch VENT port. On some engines a flexible hose is installed.
D.  Remove two screws attaching switch and bracket assembly to bracket on engine gearbox. On some engines, remove two screws attaching switch and bracket assembly to bracket on constant speed drive (CSD) oil filter.
E.  If switch is to be replaced with a new unit, remove reducer unions and O-rings.
 
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