BENDIX AD-9 AIR DRYER User's Manual

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