BENDIX SD-08-2418 Manual page 15

BENDIX
SYMPTOM
5. Cannot build system air
pressure.
6. Air dryer does not purge or
exhaust air.
7. Desiccant material being
expelled from the air dryer
purge valve exhaust (may
look like whitish liquid or
paste or small beads.)
8. Unsatisfactory desiccant
life.
9. "Pinging" noise excessive
during compressor loaded
cycle.
10. The air dryer purge piston
cycles rapidly in the
compressor unloaded (non-
compressing) mode.
AD-IS AIR DRYER & RESERVOIR SYSTEM
® ®
TROUBLESHOOTING CHART
CAUSE
A. Supply pressure to the air dryer is not
sufficient.
B. Kinked or blocked (plugged) discharge
line.
C. Excessive bends in discharge line
(water collects and freezes).
D. Pressure protection valve(s) in air
dryer will not open.
E. Refer to Symptom 4.
F. Refer to Symptom 7.
A. Faulty air dryer purge valve.
B. See Causes B, E, and F for Symptom
#4.
A. Faulty dryer cartridge.
B. Excessive dryer vibration.
A. Excessive system leakage.
B. Wrong vehicle application for a
Bendix AD-IS air dryer.
® ®
C. Compressor passing excessive oil.
A. Single cylinder compressor with high
pulse cycles.
A. Compressor fails to unload.
REMEDY
A. Ensure the supply pressure to the air dryer is greater than
110 psi after the system charges.
B. Check to determine if air passes through the discharge line.
Check for kinks, bends, excessive carbon deposits, or ice
blockage.
C. Discharge line should be constantly sloping from compressor
to air dryer with as few bends as possible.
D. Replace air dryer (pressure protection valves are not
serviceable).
E. Refer to Symptom 4, Remedy A.
F. Refer to Symptom 7, Remedies A and B.
A. After determining air reaches purge valve control port by
installing a T-fitting with a pressure gauge into the governor
unloader port, repair purge valve if necessary.
B. Refer to Symptom 4, Remedies B, E, and F.
Also refer to Symptom 1, Remedy B.
A. Replace the Bendix AD-IS
®
dryer.
B. Check the AD-IS air dryer mounting for looseness or damage.
Repair the mounting and replace the cartridge.
A. Refer to Symptom 1, Remedy A.
B. Refer to Symptom 2, Remedy C.
C. Check for proper compressor installation; if the symptoms
persist, replace the compressor. Refer to Bendix Advanced
Troubleshooting Guide for Air Brake Compressor (BW1971).
A. A slight "pinging" sound may be heard during the system build-
up when a single cylinder compressor is used. If this sound
is deemed objectionable, it can be reduced substantially by
increasing the discharge line volume.
This can be accomplished by adding a 90 cubic inch (or larger)
reservoir between the compressor and the Bendix AD-IS air
dryer & reservoir system.
A. Check air hose from the governor to the compressor for a
missing, kinked, or restricted line. Install or repair the air hose.
Repair or replace the compressor unloader.
air dryer cartridge or AD-IS air
®
15