BENDIX AD-9si Service Data page 14

SYMPTOM
2. Water in vehicle reservoirs.
3. Safety valve on air dryer
"popping off" or exhausting
air.
4. Constant exhaust of air at air
dryer purge valve exhaust
or unable to build system
pressure. (Charge mode.)
14
BENDIX AD-9si
®
TROUBLESHOOTING CHART
CAUSE
A. Maximum air dryer inlet temperature
is exceeded due to improper discharge
line length.
B. Ambient temperature exceeds 125°F.
C. Air system charged from outside air
source (outside air not passing through
air dryer).
D. Excessive air usage - Air dryer not
compatible with vehicle air system
requirement (improper air dryer/vehicle
application).
E. Desiccant requires replacement.
F. Air dryer not purging.
G. Purge (air exhaust) time insufficient due
to excessive system leakage.
A. Safety valve setting too low (<150 psi).
B. System pressure too high (>135 psi).
C. Excessive pressure pulsations from
compressor. (Typical single cylinder
type).
A. Air dryer purge valve leaking excessively. A. With the compressor loaded, apply a soap solution on the purge
B. Purge valve frozen open - faulty heater
and thermostat, wiring, blown fuse.
C. Defective AD-9si air dryer delivery
check valve.
D. Leaking turbo cut-off valve.
E. Defective governor.
F. Leaking purge valve control piston
seals.
AIR DRYER
®
A. Check for excessive carbon build-up in the compressor
discharge line. Replace if required. Make certain that the
discharge line length is at least 6 ft. Increase the discharge line
length and/or diameter to reduce air dryer inlet temperature.
B. Relocate the air dryer away from excessive heat source.
C. If the system must have outside air fill provision, outside air
should pass through the air dryer.
D. Refer to the Bendix Air Dryer Application Guideline (BW2600)
®
for proper application of the Bendix
extended purge reservoir may be added for higher air usage
vehicles, such as city buses and construction vehicles.
If the vehicle is equipped with high air usage accessories such
as trailer pump-off systems or central tire inflation, the air for
these accessories must by-pass the air dryer.
E. Replace desiccant cartridge assembly. See Recommended
Service Intervals for Bendix Air Dryers (BW8068) for
recommended service intervals.
F. Refer to Symptom 6.
G. Refer to Symptom 1.
A. Replace safety valve.
B. Test with accurate gauge. Replace the governor cartridge if
necessary.
C. Increase the volume in the discharge line. This can be
accomplished by adding a 90 cubic inch (or larger) reservoir
between the compressor and the AD-9si air dryer.
valve exhaust, to test for excessive leakage. Repair or replace
the purge valve as necessary.
B. Refer to paragraph 5 of the Operation and Leakage Tests for the
heater and thermostat test.
C. Refer to Symptom 1, Remedy B.
D. Repair or replace the purge valve assembly.
E. Check the governor at both "cut-in" and "cut-out" positions for
proper pressures and excessive leakage at the exhaust.
F. Repair or replace the purge valve assembly.
REMEDY
AD-9si air dryer. An
® ®