5
PREVENTIVE MAINTENANCE
Important:
Review the warranty policy before performing
any intrusive maintenance procedures. An extended
warranty may be voided if intrusive maintenance is
performed during this period. Purge valve maintenance
is permissible during the warranty period only when using
a genuine Bendix
®
purge valve kit.
Because no two vehicles operate under identical
conditions, maintenance and maintenance intervals will
vary. Experience is a valuable guide in determining the best
maintenance interval for any one particular operation.
Every 900 operating hours, or 25,000 miles, or three
(3) months:
1. Check for moisture in the air brake system by opening
reservoir drain valves and checking for the presence
of water. If moisture is present, the desiccant cartridge
may require replacement; however, the following
conditions can also cause water accumulation and
should be considered before replacing the desiccant:
A. An outside air source has been used to charge the
system. This air did not pass through the drying
bed.
B. Air usage is exceptionally high and not normal for
a highway vehicle.
This may be due to accessory air demands or some
unusual air requirement that does not allow the
compressor to load and unload (compressing and
non-compressing cycle) in a normal fashion. Check
for high air system leakage. If the vehicle vocation
has changed, it may be necessary to upgrade the
compressor size. Refer to Bendix Specifi cation
BW-100-A / Appendix D, to determine if any changes
are necessary. Specifi cation BW-100-A is available
from the Bendix TechTeam at 1-800-247-2725 or
www.bendix.com.
C. The location of the air dryer and reservoir system
is too close to the air compressor. Refer to Bendix
Specifi cation BW-110-A / Appendix B, for discharge
line lengths.
D. In areas where more than a 30 degree range of
temperature occurs in one day, small amounts
of water can temporarily accumulate in the air
brake system due to condensation. Under these
conditions, the presence of small amounts of
moisture is normal.
For Bendix
®
AD-IS
®
PuraGuard
®
oil coalescing
air dryers only - every 3,600 operating hours, or
100,000 miles, or 12 months:
Oil removal requirements for air brake quality vary
by vehicle manufacturer. Because vehicle vocation
and maintenance can infl uence when the Bendix
®
AD-IS
®
PuraGuard
®
oil coalescing air dryer cartridge
requires replacement, each fl eet should modify their
replacement schedule based on experience. The
change out interval will be extended if the compressor
passes a low level of particles. The interval will be
reduced if excessive carbon particles are delivered to
the dryer inlet. Higher compressor build up times at
idle, as well as water or oil in downstream reservoirs
indicate an AD-IS PuraGuard oil coalescing air dryer
desiccant cartridge may need to be replaced.
Note: A small amount of oil in the system is normal and
should not be considered as a reason to replace the
desiccant cartridge. Some oil at the dryer exhaust is
also normal.
2. Visually check for physical damage, such as chaffed or
broken air and electrical lines, and broken or missing
parts.
3. Check
the
AD-IS
®
air dryer and purge reservoir bolts for
tightness. See Figure 1. Re-torque the three air dryer
bolts to 360–420 in-lbs and the four purge reservoir
bolts to 300–360 in-lbs.
4. Perform the Operation & Leakage Tests listed in this
publication.
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 and
reservoir system. Alcohol is removed by the dryer,
but reduces the effectiveness of the device to dry air.
Use of these or other substances can damage the air
dryer and may void the warranty.
FIGURE 4 - HEATER AND THERMOSTAT CONNECTOR
HEATER & THERMOSTAT
CONNECTOR
