BENDIX SD-08-2418 Manual page 14

BENDIX
SYMPTOM
2. Water in the vehicle
reservoirs.
3. Safety valve on the air
dryer is "popping off" or
exhausting air.
4. Constant exhaust of air at
the air dryer purge valve
exhaust or unable to build
system pressure. (Charge
mode.)
14
AD-IS AIR DRYER & RESERVOIR SYSTEM
® ®
TROUBLESHOOTING CHART
CAUSE
A. Maximum air dryer inlet temperature is
exceeded due to improper discharge
line length.
B. Air system charged from outside
air source (outside air not passing
through the air dryer).
C. Excessive air usage – Air dryer not
compatible with the vehicle air system
requirement (Improper air dryer/
vehicle application).
D. Desiccant requires replacement.
E. Air by-passes desiccant cartridge
assembly.
F. Air dryer not purging.
G. Purge (air exhaust) time is insufficient
due to excessive system leakage.
A. Defective AD-IS air dryer & reservoir
system delivery check valve.
B. Safety valve setting too low (<150 psi) B. Replace the safety valve.
C. System pressure too high (>135 psi)
D. Excessive pressure pulsations from
compressor. (Typical single cylinder
type).
A. Air dryer purge valve leaking
excessively.
B. Purge valve frozen open – faulty heater
and thermostat, wiring, or blown fuse.
C. Defective Bendix AD-IS
®
delivery check valve.
D. Leaking turbo cut-off valve.
E. Defective governor.
F. Leaking purge valve control piston
seals.
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. If the system must have an outside air fill provision, the outside
air should pass through the air dryer.
C. Refer to the Bendix Advanced Troubleshooting Guide for Air
Brake Compressors (BW1971) for proper application of the
Bendix AD-IS
®
purge model (Bendix
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 dryer reservoir
system.
D. Replace the desiccant cartridge assembly.
E. If the vehicle uses a Holset
check valve for proper installation and operation.
F. Refer to Symptom 6.
G. Refer to Symptom 1.
A. Test to determine if air is passing through the check valve.
Repair or replace. Refer to Symptom 1, Remedy B.
C. Test with an accurate gauge. Replace the governor if
necessary.
D. 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 & reservoir system.
A. With the compressor loaded, apply a soap solution on the
purge 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.
air dryer 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 (i) proper pressures and (ii) excessive leakage at fittings
and exhaust.
F. Repair or replace the purge valve assembly.
REMEDY
air dryer & reservoir system. An extended
®
AD-IS EP) is available for many higher
® ®
compressor, inspect the feedback
®