Bendix Commercial Vehicle Systems DRM DRYER RESERVOIR MODULE 3/07 - Manual (Page 12)

12
DRM ™ /AD-IS ® AIR DRYER TROUBLESHOOTING CHART (Continued)
SYMPTOMS CAUSE REMEDY
C. Refer to Symptom 1, Remedy B.
D. Repair or replace purge valve assembly.
E. Check governor at both “cut-in” and “cut-out”
position for (i) proper pressures and (ii)
excessive leakage at fittings and exhaust.
F. Repair or replace purge valve assembly.
C. Defective AD-IS ® air
dryer delivery check
valve.
D. Leaking Turbo Cutoff
valve.
E. Defective governor.
F. Leaking purge valve
control piston quad-ring.
B. System pressure too
high (>135 p.s.i.)
C. Excessive pressure
pulsations from
compressor. (Typical
single cylinder type).
D. Safety valve setting too
low (<150 p.s.i.)
A. Test to determine if air is passing through check
valve. Repair or replace. Refer to Symptom 1,
Remedy B.
B. Test with accurate gauge. Replace governor if
necessary.
C. Increase volume in discharge line. This can be
accomplished by adding a 90 cubic inch (or
larger) reservoir between the compressor and the
AD-IS
® air dryer.
D. Replace safety valve.
3. Safety valve on air dryer
“popping off” or
exhausting air.
A. Defective AD-IS ® air
dryer delivery check
valve.
4. Constant exhaust of air
at air dryer purge valve
exhaust or unable to
build system pressure.
(Charge mode.)
A. With compressor loaded, apply soap solution
on purge valve exhaust, to test for excessive
leakage. Repair or replace purge valve as
necessary.
B. Refer to paragraph 5 of Operation and Leakage
Tests for heater and thermostat test.
A. Air dryer purge valve
leaking excessively.
B. Purge valve frozen open
- faulty heater and
thermostat, wiring,
blown fuse.