Bendix Commercial Vehicle Systems AD-RP PuraGuard Oil Coalescing Remote Purge Air Dryers - Manual (Page 18)

18
Bendix ® AD-RP ™ AIR DRYER TROUBLESHOOTING CHART
SYMPTOMS CAUSE REMEDY
1. Air dryer is constantly
“cycling” or purging.
Air dryer purges
frequently (every 4
minutes or less) while
vehicle is idling.
B. Incorrect governor setting or
malfunctioning governor.
B. Minimum setting required for Bendix ® AD-RP ™ air
dryer installation is 100 psi cut-in and 120 psi cut-out.
Test operation of the governor. Repair or replace as
necessary.
C. Rapid cycling of the
governor due to air
starvation at the reservoir
(RES) port of the governor.
C. With a gauge installed at the RES port of the
governor, the pressure should not drop below cut-in
pressure at the onset of the compressor "unloaded"
cycle. If the pressure drops, check for "kinks" or
restrictions in the line connected to the RES port.
The line connected to the RES port on the governor
must be the same diameter, or preferably larger, than
the lines connected to the UNL port(s) on governor.
D. High air usage vehicle
application.
D. Refer to the "Vehicle Application Requirements"
section of this manual and verify the 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.
A. Refer to the section titled "Connecting the Air Lines"
and Appendix A / Table A / columns 1 & 2, then check
the line size and length.
B. Air system charged from an
outside air source (outside
air not passing through air
dryer).
B. If the system must have an outside air fi ll provision,
outside air should pass through air dryer. This
practice should be minimized.
C. Air dryer is not purging. C. See Symptom #5.
D. Purge (air exhaust) time
insuffi cient due to excessive
system leakage.
D. Check causes and remedies for Symptom #1.
(continued)