BENDIX SD-08-2417 Manuale Utente

Before placing the vehicle in service, perform the following 

tests.
1.  Close all reservoir drain valves.
2.  Build up system pressure to governor cut-out and note 

that one Bendix

®

 AD-IS

®

 air dryer purges with an audible 

burst of air, followed immediately by approximately 30 

seconds of air flowing out of the purge valve.

3.  Apply and release the service brakes several times to 

reduce system air pressure to governor cut-in.  Note 

that the system once again builds to full pressure and is 

followed by a purge at the other AD-IS air dryer exhaust.

4.  It is recommended that the total air system be tested 

for leakage to ensure that the AD-IS air dryer will not 

cycle excessively.

See Bendix publication BW5057 “Air Brake Handbook" for 

additional information. 

The Bendix

® 

 AD-IS

®

 EverFlow

® 

assembly allows the system 

to maintain one brake circuit up to about 100 psi even after 

a pressure loss in the other brake circuit.  This allows a 

vehicle to be moved (in an emergency), but with reduced 

braking capacity.  Compare this to a conventional system 

where a loss of pressure in one service tank leaves the 

vehicle with a limited number of reduced braking capacity 

applications before the parking brakes automatically apply 

and stay on.

In the event of a roadside inspection, the system behavior 

will  be  as  follows:    When  the  system  is  charged  to 

governor cut-out, and then one reservoir drain valve is 

opened, initially both reservoir gauges will fall, however, 

the EverFlow assembly primary and secondary pressure 

protection valves will close at pressures above 70 psi, 

protecting the remaining brake circuit from further loss 

of pressure.

To temporarily bypass the EverFlow 

 

assembly, the 

following procedure needs to be followed.
Follow the General Safety Guidelines outlined on page 2 

in this document.
Make sure that all residual pressure has been released 

and the air dryer purge reservoir has been drained to 0 

psi,  then remove the air supply line from the compressor 

to the inlet port (1 IN).  Remove the safety valve from the 

AD-IS air dryer body (see Figure 1 for location).  Note that 

a short puff of trapped air may vent from the safety valve 

port when the valve is being removed.  Install a T-fitting 

into the port.

Using any adapters necessary, reinstall the safety valve in 

one of the branches of the T-fitting.  Using any adapters 

necessary, install the air supply line into the remaining  

T-fitting port.  After testing the T-fitting for any air leakage, 

by using a soap solution after charging to system cut-out 

pressure (a 1” bubble in 10 seconds is acceptable), the 

vehicle may be returned to temporary service.
Note:  This is a temporary bypass of the air dryer, and 

opportunity.  With the EverFlow

 

assembly removed from 

the system, contaminants will be entering the air system:  

reservoirs will need to be manually drained daily until the 

repairs are completed.  At the end of each working day, 

park vehicle and slowly drain pressure through the drain 

valves – leave open to the atmosphere, for several hours 

if possible.  When repairs are carried out, be sure to check 

that all reservoirs (including the air dryer purge reservoir) 

are emptied of all contaminants.
If after bypassing the EverFlow

 

assembly the system 

pressure still does not build, use the following procedure 

to remove, clean and reinstall the delivery check valve. 

PRESSURE 

PROTECTION 

VALVE 

LOCATIONS

BENDIX

® 

AD-IS

®

AIR DRYER 

GOVERNORS

ARE NON-

ADJUSTABLE

AND FEATURE A 

BREATHER VALVE 

IN THIS PORT