Bendix Commercial Vehicle Systems AD-9 IPC AIR DRYERS 4/11 - Manual (Page 23)

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Bendix ® AD-9 ® AND AD-9 ® IPC AIR DRYER TROUBLESHOOTING CHART
SYMPTOMS CAUSE REMEDY
2. Water and/or Oil in Supply
o r S e r v i c e R e s e r v o i r
(continued).
(Continued) Purge Cycle Time - During normal vehicle operation, the
air compressor must remain unloaded for a minimum of 20
seconds for the standard Bendix
® AD-9 ® and AD-9 ® IPC air
dryer or 30 seconds for the extended purge model. These
minimum purge times are required to ensure complete
regeneration of the desiccant material. If the purge time is
consistently less than the minimum, an accessory by-pass
system must be installed. Consult your local authorized Bendix
parts outlet or sales representative for additional information.
European Air Brake Systems - Brake systems that incorporate
compressors without integral unloading mechanisms and/
or utilize a compressor discharge line unloader valve have
special air dryer installation requirements. Consult your local
authorized Bendix parts outlet or sales representative for
additional information.
Air Compressor Size - Although the AD-9 and AD-9
IPC air dryers can be used in conjunction with larger
compressors, it was designed primarily for units rated for
up to 17 CFM. It is recommended that when using the
AD-9 or AD-9 IPC air dryer with a compressor which has a
rated displacement exceeding 17 CFM that an authorized
Bendix parts outlet or Bendix marketing representative
be contacted for assistance.
G. Air compressor discharge and/or
air dryer inlet temperature too high.
G. Restricted discharge line. See Appendix A, Table A, column 1
& 2 for recommended sizes. If discharge line is restricted or
more than 1/16” carbon build up is found, replace the discharge
line. Replace as necessary.
Discharge Line Freeze-Up. The discharge line must maintain a
constant slope down from the compressor to the air dryer inlet
fi tting to avoid low points where ice may form and block the fl ow.
If, instead, ice blockages occur at the air dryer inlet, insulation
may be added here, or if the inlet fi tting is a typical 90 degree
fi tting, it may be changed to a straight or 45 degree fi tting. For
more information on how to help prevent discharge line freeze-
ups, see Bendix Bulletins TCH-008-021 and TCH-008-022.
Shorter discharge line lengths or insulation may be required in
cold climates.
Insuffi cient coolant fl ow through compressor. Inspect coolant line.
Replace as necessary (I.D. is 1/2” min.). Inspect the coolant lines
for kinks and restrictions and fi ttings for restrictions. Replace as
necessary. Verify coolant lines go from engine block to compressor
and back to the water pump. Repair as necessary.
Restricted air inlet (not enough air to compressor). Check
compressor air inlet line for restrictions, brittleness, soft or sagging
hose conditions, etc. Repair as necessary. Inlet line size is 3/4 ID.
Maximum restriction requirement for compressors is 25 inches
of water. Check the engine air fi lter and service if necessary (if
possible, check the air fi lter usage indicator).