BENDIX SD-08-2418 Manuel D’Utilisation

2.  Water in the vehicle 

reservoirs

A.  Maximum air dryer inlet temperature is 

exceeded due to improper discharge 

line length. 

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.  Air system charged from outside 

air source (outside air not passing 

through air dryer).  

B.  If system must have outside air fill provision, outside air should 

pass through air dryer. 

C.  Excessive air usage - Air dryer not 

compatible with the vehicle air system 

requirement (Improper air dryer/

vehicle application)

C.  Refer to the Bendix Advanced Troubleshooting Guide for Air 

Brake Compressors (BW1971) for proper application of the 

Bendix

®

 AD-IS

®

 air dryer and reservoir system.  An extended 

purge model (Bendix

®

 AD-IS

® 

EP) is available for many 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 dryer reservoir 

system.

D.  Desiccant requires replacement. 

D. Replace the desiccant cartridge assembly.

E.  Air by-passes desiccant cartridge 

assembly.

E. If the vehicle uses a Holset compressor, inspect the feedback 

check valve for proper installation and operation. 

F.  Air dryer not purging. 

F.  Refer to Symptom 6.

G.  Purge (air exhaust) time is insufficient 

due to excessive system leakage. 

G.  Refer to Symptom 1.

3.  Safety valve on the air dryer  

is “popping off” or exhausting 

air.  

A.  Defective AD-IS air dryer and reservoir 

system delivery check valve.  

A.  Test to determine if air is passing through check valve. Repair 

or replace.  Refer to Symptom 1, Remedy B.

B.  Safety valve setting too low (<150 p.s.i.) B.  Replace the safety valve.
C.  System pressure too high (>135 p.s.i.) C.  Test with an accurate gauge. Replace the governor if 

necessary.

D.  Excessive pressure pulsations from 

compressor. (Typical single cylinder 

type).  

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 and reservoir system.