BENDIX AD-4 AIR DRYER Manual page 21

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AD-4 AIR DRYER TROUBLESHOOTING CHART (Continued)
SYMPTOMS
8. Desiccant material being
expelled from air dryer
purge valve exhaust
(may look like whitish
liquid or paste or small
beads.)
- OR -
Unsatisfactory desiccant
life.
9. "Pinging" noise
excessive during
compressor loaded
cycle.
10. Constant seepage of air
at air dryer purge valve
exhaust (non-charging
mode.)
11. The air dryer purge
piston cycles rapidly in
the compressor
unloaded (non-
compressing) mode.
CAUSE
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.
B. Air dryer not securely
mounted. (Excessive
vibration.)
C. Malfunctioning or
saturated desiccant
cartridge.
D. Compressor passing
excessive oil.
E. Desiccant cartridge not
assembled properly to
end cover. (Loose
attachment)
A. Single cylinder
compressor with high
pulse cycles.
A. Defective check valve
™
assembly in AD-4 air
dryer end cover.
B. Leaking Turbo Cutoff
valve.
C. Leaking purge valve
control piston o-ring.
A. Compressor fails to
"unload".
REMEDY
A. See Causes and Remedies for Symptoms 1, 2,
3, 4 and 5.
B. Vibration should be held to minimum. Add
bracket supports or change air dryer mounting
location if necessary.
C. Replace desiccant cartridge assembly.
D. Check for proper compressor installation; if
symptoms persist, replace compressor.
E. Check the torque on the desiccant cartridge
to end cover attachment. Refer to assembly
section of this data sheet.
A. A slight "pinging" sound may be heard during
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 AD-4 ™ air dryer. IMPORTANT: Do not
exceed the line lengths requirements specified
in this manual.
A. Refer to Remedy C, Symptom #1.
B. Repair or replace purge valve assembly.
C. Repair or replace purge valve assembly.
A. Faulty governor installation; no air line from
governor to compressor or line is kinked or
restricted. Install or repair air line.
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