Bendix Commercial Vehicle Systems AD-9si Oil Coalescing Air Dryer - Manual (Page 8)

8
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 and governor
maintenance is permissible during the warranty period
only when using a genuine Bendix ® AD-9si ™ purge valve
governor 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 of the air dryer.
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. Contact the Bendix TechTeam
at1-800-AIR-BRAKE (1-800-247-2725), option 2,
or www.bendix.com for more information.
C. The location of the air dryer is too close to the air
compressor. See the troubleshooting chart at the
end of this document (Symptom 2 - Remedy A).
D. In areas where more than a 30° 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-9si air dryers: Preventive Maintenance
is as easy as 1-2-3
Adhering to a preventive maintenance schedule is crucial
to keeping a vehicle’s air system clean and ensuring
superior performance of all components that utilize
system air— such as brakes, emissions equipment
and automated manual transmissions. Depending on
vocation, Bendix recommends a 1-, 2- or 3-year air dryer
cartridge replacement on vehicles equipped with a Bendix ®
compressor.
For severe service application — such as residential
refuse trucks or school buses — the air dryer cartridge
should be replaced every year or 100,000 miles; for pick-
up and delivery operations, or for double- and triple-trailer
line haul trucks, every two years or 200,000 miles is the
recommendation. Line-haul operations using a single trailer
should swap the filter out every three (3) years or 300,000
miles. The recommended intervals for trucks equipped with
non-Bendix compressors are six months (50,000 miles),
one year (100,000 miles), and two years (200,000 miles),
respectively.
More frequent intervals may be required depending
on a vehicle’s age, its compressor condition, use of a
non-Bendix compressor, the operating environment, the
vehicle’s vocation, and its usage. In conjunction with these
guidelines, fleets can determine the functionality of their
filters by checking for moisture in the air brake system
monthly. If moisture is present, the air dryer cartridge may
require replacement. Reference the Bendix Service Data
Sheet of the specific air dryer for additional information.
(Recommended intervals for trucks equipped with non-
Bendix compressors are six months (50,000 miles), one
year (100,000 miles), and two years (200,000 miles),
respectively.)
FIGURE 6 - HEATER AND THERMOSTAT CONNECTOR
HEATER & THERMOSTAT
CONNECTOR