User's Manual

12
TROUBLESHOOTING CHART (Continued)
SYMPTOM
CAUSE
REMEDY
D. Replace desiccant cartridge assembly.
D. Desiccant requires
replacement.
E. Air by-passes desiccant
cartridge assembly.
F. Air dryer not purging.
G. Purge (air exhaust) time
insufficient due to
excessive system
leakage.
A. Maximum air dryer inlet
temperature is
exceeded due to
improper discharge line
length.
B. Air system charged from
outside air source
(outside air not passing
through air dryer).
C. Excessive air usage -
Air dryer not compatible
with vehicle air system
requirement (Improper
air dryer/vehicle
application).
A. Check for excessive carbon build up in
compressor discharge line. Replace if
required. Make certain that discharge line
length is at least 6 ft. Increase discharge line
length and/or diameter to reduce air dryer inlet
temperature.
B. If system must have outside air fill provision,
outside air should pass through air dryer.
2. Water in vehicle
reservoirs.
C. Refer to Bendix Advanced Troubleshooting Guide
for Air Brake Compressors (BW1971) for proper
application of the AD-IS
®
air dryer and reservoir
system. An extended purge model (AD-ISEP) is
available for many higher air usage vehicles,
such as city buses and construction vehicles.
If the vehicle is equipped with high air usage
accessories such as trailer pump-off systems or
central tire inflation, the air for these accessories
must by-pass the dryer reservoir system.
F. Refer to Symptom 6.
E. If vehicle uses Holset compressor, inspect
feedback check valve for proper installation and
operation.
G. Refer to Symptom 1.