Bendix Commercial Vehicle Systems DRM DRYER RESERVOIR MODULE 3/07 - Manual (Page 11)

11
DRM ™ /AD-IS ® AIR DRYER TROUBLESHOOTING CHART (Continued)
SYMPTOMS 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. Note: The AD-IS ® air dryer is not intended for
use on applications with excessive air usage.
The following applications require more dry air
than the AD-IS
® air dryer is designed to supply.
Do not use on:
1) City buses.
2) Vehicle combinations with more than 8 braked
axles.
3) City refuse vehicles except those with work
brakes.
4) Concrete mixers.
5) Dump trucks with more than 3 axles.
6) Off-highway/construction vehicles with more
than 7 braked axles.
7) Vehicles with compressor on times in excess
of 20%.
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.
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.