Bendix Commercial Vehicle Systems AD-SP SYSTEM PURGE AIR DRYER 10/04 - Manual (Page 18)

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AD-SP ™ AIR DRYER TROUBLESHOOTING CHART (Continued)
SYMPTOMS CAUSE REMEDY
B. Locate the SC-PR ™ valve on the front axle
service (secondary) reservoir and replace.
C. Minimum setting required for AD-SP ™ air dryer
installation 100 cut in and 120 cut out. Test
operation of governor. Repair or replace as
necessary.
D. With gauge installed at RES port of governor,
pressure should not drop below "Cut In"
pressure at the onset of the compressor
"Unloaded" cycle. If pressure drops, check for
"kinks" or restrictions in line connected to RES
port. Line connected to RES port on governor
must be same diameter, or preferably larger
than, lines connected to UNL port(s) on
governor.
E. Eliminate all leakage possibilities in 1A -
Replace AD-SP ™ air dryer.
F. Refer to the "Vehicle Application
Requirements" section of this manual and
verify application.
B. Leaking (internal or
external) SC-PR ™ single
check protection valve.
C. Incorrect governor setting
or malfunctioning
governor.
D. Rapid cycling of the
governor due to air
starvation at the RES
port of the governor.
E. Leaking purge control
mechanism or delivery
check valve in AD-SP
™
air dryer.
F. High air usage - Vehicle
application.
2. Water and/or Oil in
Supply or Service
Reservoir.
A. Improper discharge line
length or improper line
material. Maximum air
dryer inlet temperature is
exceeded.
B. Air system charged from
outside air source
(outside air not passing
through air dryer).
C. Air dryer not purging
(see Symptom #5).
A. Refer to section entitled Connecting the Air Lines
as well as Appendix A, Table A columns 1 & 2
then and check line size and length.
B. If system must have outside air fill provision,
outside air should pass through air dryer. This
practice should be minimized.
C. See Symptom #5.
D. Purge (air exhaust) time
insufficient due to
excessive system
leakage (see causes for
Symptom #1).
D. Check causes and remedies for Symptom #1.
E. Excessive air usage,
duty cycle too high - Air
dryer not compatible
with vehicle air system
requirement (Improper air
dryer/vehicle
application).
E. See Appendix A, Table A, column 1, for
recommended compressor sizes. If the
compressor is “too small” for the vehicle vocation
(for example, where a vehicle’s vocation has
changed or service conditions exceed the
original vehicle or engine OE spec’s) then
upgrade the compressor. Note: The costs
incurred (e.g. installing a larger capacity
compressor, etc.) are not covered under original
compressor warranty.