BENDIX SD-08-2418, Manual

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15
BENDIX
®
AD-IS
®
AIR DRYER & RESERVOIR SYSTEM
TROUBLESHOOTING CHART
SYMPTOM CAUSE REMEDY
5. Cannot build system air
pressure.
A. Supply pressure to the air dryer is not
sufficient.
A. Ensure the supply pressure to the air dryer is greater than
110 psi after the system charges.
B. Kinked or blocked (plugged) discharge
line.
B. Check to determine if air passes through the discharge line.
Check for kinks, bends, excessive carbon deposits, or ice
blockage.
C. Excessive bends in discharge line
(water collects and freezes).
C. Discharge line should be constantly sloping from compressor
to air dryer with as few bends as possible.
D. Pressure protection valve(s) in air
dryer will not open.
D. Replace air dryer (pressure protection valves are not
serviceable).
E. Refer to Symptom 4. E. Refer to Symptom 4, Remedy A.
F. Refer to Symptom 7. F. Refer to Symptom 7, Remedies A and B.
6. Air dryer does not purge or
exhaust air.
A. Faulty air dryer purge valve. 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. See Causes B, E, and F for Symptom
#4. B. Refer to Symptom 4, Remedies B, E, and F.
Also refer to Symptom 1, Remedy B.
7. Desiccant material being
expelled from the air dryer
purge valve exhaust (may
look like whitish liquid or
paste or small beads.)
A. Faulty dryer cartridge. A. Replace the Bendix
®
AD-IS
®
air dryer cartridge or AD-IS air
dryer.
B. Excessive dryer vibration. B. Check the AD-IS air dryer mounting for looseness or damage.
Repair the mounting and replace the cartridge.
8. Unsatisfactory desiccant
life.
A. Excessive system leakage. A. Refer to Symptom 1, Remedy A.
B. Wrong vehicle application for a
Bendix ® AD-IS ® air dryer.
B. Refer to Symptom 2, Remedy C.
C. Compressor passing excessive oil. C. Check for proper compressor installation; if the symptoms
persist, replace the compressor. Refer to Bendix Advanced
Troubleshooting Guide for Air Brake Compressor (BW1971) .
9. “Pinging” noise excessive
during compressor loaded
cycle.
A. Single cylinder compressor with high
pulse cycles.
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.
10. The air dryer purge piston
cycles rapidly in the
compressor unloaded (non-
compressing) mode.
A. Compressor fails to unload. 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.