Bendix Commercial Vehicle Systems AD-SP SYSTEM PURGE AIR DRYER 10/04 - Manual (Page 25)

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BENDIX ® AD-IP ® AIR DRYER TROUBLESHOOTING CHART
SYMPTOMS CAUSE REMEDY
8. Desiccant material
being expelled from
the air dryer purge
valve exhaust (may
look like whitish liquid
or paste or small
beads.)
- OR -
Unsatisfactory
desiccant life.
A. This symptom is almost
always accompanied by
one, or more, of Symptoms
1, 2, 3, 4 and 5. See related
causes for these symptoms
above.
A. See Causes and Remedies for Symptoms 1, 2, 3,
4 and 5.
B. Air dryer not securely
mounted. (Excessive
vibration.)
B. Vibration should be held to minimum. Add bracket
supports or change the air dryer mounting location
if necessary.
C. Malfunctioning or saturated
desiccant cartridge.
C. Replace the desiccant cartridge assembly.
D. Compressor passing
excessive oil.
D. Check for proper compressor installation; if
symptoms persist, replace the compressor.
E. Desiccant cartridge not
assembled properly to
the end cover. (Loose
attachment.)
E. Check the torque on the desiccant cartridge
to end cover attachment. Refer to the assembly
section of this data sheet.
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 an additional
four feet of discharge line or adding a 90 cubic
inch reservoir between the compressor and the air
dryer. IMPORTANT: Do not exceed the line lengths
requirements specified in this manual.
10. Constant seepage of
air at air dryer purge
valve exhaust (non-
charging mode.)
A. Defective check valve
assembly in Bendix ® AD-IP ®
air dryer end cover.
A. Refer to Remedy C, Symptom #1.
B. Leaking turbo cut-off valve. B. Repair or replace purge valve assembly
C. Leaking purge valve control
piston o-ring.
C. Repair or replace purge valve assembly.
11. The air dryer purge
piston cycles rapidly
in the compressor
unloaded (non-
compressing) mode.
A. Compressor fails to “unload”. A. Faulty governor installation; no air line from the
governor to the compressor or the air line is kinked
or restricted. Install or repair the air line.