12.4
Check for excessive leakage around the
head of the desiccant cartridge where it
contacts the end cover. With the com-
pressor in loaded mode (compressing
air), apply a soapy solution to these
areas, and observe that any leakage
does not exceed a 1-inch bubble in 1
second. If leakage exceeds this measure,
remove and re-install the desiccant
cartridge.
AD-9si and AD–IS
1.
Park the vehicle on a level surface, apply the
parking brakes, and chock the tires.
2.
Drain the air reservoirs.
3.
Using a strap wrench or equivalent, loosen the
desiccant cartridge. Spin the cartridge off by
hand and discard it. See
4.
On the new desiccant cartridge, lubricate the
sealing rings with silicone grease.
IMPORTANT: Only use the silicone grease sup-
plied with Bendix replacement kits.
5.
Screw the desiccant cartridge onto the body by
hand until the seal makes contact with the body.
Rotate the cartridge clockwise about one full
turn. Tighten the cartridge firmly.
42–03 Governor D–2A Check
IMPORTANT: Review the warranty policy before
performing any intrusive maintenance proce-
dures. An extended warranty may be voided if
intrusive maintenance is performed during this
period.
Every 12 months, 100,000 miles (160 900 km), or
3600 operating hours, perform the operational test
below.
Operational Test
1.
Start the vehicle engine, build air pressure in the
brake system, and check the pressure registered
by a dash or test gauge at the time the governor
cuts-out, stopping the compression of air by the
compressor. Cut-out pressure should be in ac-
cordance with the pressure setting of the piece
number being used. Common cut-out pressures
are 125 to 135 psi (862 to 931 kPa). With the
engine still running, make a series of brake appli-
cations to reduce the air pressure, and observe
at what pressure the governor cuts-in the com-
pressor. As in the case of cut-out pressure, cut-in
pressure should be in accordance with the pres-
sure setting of the piece number being used.
Cut-in pressure is 105 psi (724 kPa).
NOTE: If the governor cover is marked nonad-
justable, and the adjusting stem has been
sheared off, this is a non-serviceable governor
and it must be replaced with a new or remanu-
factured unit.
2.
Never condemn or adjust the governor pressure
settings unless they’re checked with an accurate
test gauge or a dash gauge that’s registering ac-
curately. If the pressure settings of the D-2 gov-
ernor are inaccurate or it’s necessary that they
be changed, the adjustment procedure follows.
2.1
Remove the top cover from the governor.
2.2
Loosen the adjusting screw locknut.
2.3
To raise the pressure setting, turn the ad-
justing screw counterclockwise; to lower
the setting, turn the screw clockwise. Be
careful not to overadjust. Each 1/4 turn of
the adjusting screw raises or lowers the
pressure setting approximately 4 psi (28
kPa).
f421
9
10
10/07/2016
1
2
3
1.
Desiccant Cartridge
2.
Cartridge Sealing Ring
3.
Threaded Base Post
Fig. 3, Desiccant Cartridge Replacement
Brakes
42
Business Class M2 Maintenance Manual, November 2015
42/4
Property of American Airlines
