1

CONTROL

PORT

SUPPLY

PORT

SD-08-2412

Bendix

®

AD-9

™

Air Dryer

EXTENDED PURGE AD-9

™

AIR DRYER

STANDARD AD-9

™

AIR DRYER

OUTER

SHELL

WIRING HARNESS

CONNECTION

DELIVERY PORT

DESCRIPTION

The function of the AD-9

™

air dryer is to collect and remove

air system contaminants in solid, liquid and vapor form before

they enter the brake system. It provides clean, dry air to the

components of the brake system which increases the life of

the system and reduces maintenance costs. Daily manual

draining of the reservoirs is eliminated.

The AD-9

™

air dryer consists of a desiccant cartridge and a

die cast aluminum end cover secured to a cylindrical steel

outer shell with eight cap screws and nuts. The end cover

contains a check valve assembly, a safety valve, three

threaded air connections and the purge valve housing

assembly. The removable purge valve housing assembly

incorporates a purge valve mechanism and a turbo charger

cut-off feature that is designed to prevent loss of engine

“turbo” boost pressure during the purge cycle of the AD-9

™

air dryer. For ease of serviceability, the desiccant cartridge

and discharge check valve assembly are screw in type. The

purge valve housing assembly, which includes the heater

and thermostat assembly, and the discharge check valve

assembly, is serviceable from the exterior of the air dryer,

while servicing the screw-in desiccant cartridge requires

removal of the air dryer assembly from the vehicle.

The AD-9

™

air dryer has three female pipe thread air

connections and each is identified as follows:

Port l.D.

Function/Connection

CON 4 ............... Control Port

(purge valve control and turbo cut-off).

SUP 11 ............. Supply Port (air in).

DEL 2 ............... Delivery Port (air out).

OUTER

SHELL

SUPPLY

PORT

WIRING HARNESS

CONNECTION

DELIVERY PORT

CHECK

VALVE

ASSEMBLY

END COVER

CHECK

VALVE

ASSEMBLY

END COVER

CONTROL

PORT

FIGURE 1 - AD-9

™

AIR DRYER MODELS