BENDIX AD-9 AIR DRYER User's Manual | Page 5

BENDIX Dryer User's Manual - AD-9 AIR DRYER.
Download
Page  of 24
4.7, 1490 votes
background image

5

and should not be considered as an indication that
the dryer is not performing properly.

Note: A small amount of oil in the system may be normal
and should not, in itself, be considered a reason to
replace the desiccant; oil stained desiccant can function
adequately.

2. Check mounting bolts for tightness. Retorque to 270-

385 inch pounds.

3. Perform the Operation & Leakage Tests listed in this

publication.

Every 10,800 hours; 300,000 miles or 36 months:

1. Rebuild the air dryer including the desiccant cartridge.

Note: The desiccant change interval may vary from vehicle
to vehicle. Although typical desiccant cartridge life is three
years, many will perform adequately for a longer period of
time. In order to take maximum advantage of desiccant life
and assure that replacement occurs only when necessary,
it is important that Operation & Leakage Tests be performed.

WARNING!

This air dryer is intended to remove moisture and other
contaminants normally found in the air brake system.
Do not inject alcohol, anti-freeze, or other de-icing
substances into or upstream of the air dryer.  Alcohol
is removed by the dryer, but reduces the effectiveness
of the device to dry air.  Use of other substances can
damage the air dryer and may void the warranty.

OPERATION & LEAKAGE TESTS

1. Test the outlet port check valve assembly by building

the air system to governor cut-out and observing a test
air gauge installed in the #1 reservoir. A rapid loss of
pressure could indicate a failed outlet port check valve.
This can be confirmed by bleeding the system down,
removing the check valve assembly from the end cover,
subject air pressure to the unit and apply a soap solution
to the check valve side. Leakage should not exceed a 1”
bubble in 1 second.

2. Check for excessive leakage around the purge valve.

With the compressor in loaded mode (compressing air),
apply a soap solution to the purge valve housing
assembly exhaust port and observe that leakage does
not exceed a 1” bubble in 1 second. If the leakage
exceeds the maximum specified, service the purge valve
housing assembly.

3. Close all reservoir drain cocks. Build up system pressure

to governor cut-out and note that AD-9™ air dryer purges
with an audible escape of air. “Fan” the service brakes
to reduce system air pressure to governor cut-in. Note
that the system once again builds to full pressure and is
followed by an AD-9™ air dryer purge.

LOWER

MOUNTING

BRACKET

AD-9™

AIR DRYER

AD-9™

END COVER

FEMALE

CONNECTOR

MALE

CONNECTOR

LATCH MUST BE

INSERTED UNTIL

IT SNAPS OVER

TAB ON MATING

CONNECTOR

SIDE VIEW

END VIEW

A two lead, 12 inch, wire harness with attached weather
resistant connector is supplied with all retrofit and
replacement AD-9™ air dryers. Connect one of the two
leads of the wire harness to the engine kill or ignition
switch. The remaining lead of the wire harness must be
connected to a good vehicle ground. A fuse should be
installed in the power carrying wire; install a 10 amp fuse
for 12 volt heaters and a 5 amp fuse for a 24 volt heater.
Use 14 AWG wire if it is necessary to lengthen the wire
harness provided.
Make certain all wire splices are waterproofed.
Tie wrap or support all electrical wire leading to the
AD-9™ air dryer.

FIGURE 6 - HEATER AND THERMOSTAT CONNECTOR

4. Check the operation of the safety valve by pulling the

exposed stem while the compressor is loaded
(compressing air). There must be an exhaust of air while
the stem is held and the valve should re-seat when the
stem is released.

5. Check all lines and fittings leading to and from the air

dryer for leakage and integrity.

6. Check the operation of the end cover heater and

thermostat assembly during cold weather operation as
follows:

A. Electric Power to the Dryer

With the ignition or engine kill switch in the ON
position, check for voltage to the heater and
thermostat assembly using a voltmeter or test light.
Unplug the electrical connector at the air dryer and
place the test leads on each of the pins of the male
connector. If there is no voltage, look for a blown
fuse, broken wires, or corrosion in the vehicle wiring
harness. Check to see if a good ground path exists.

 

0.510186s