1
®
SD-08-2407
Bendix
®
AD-4
™
Air Dryer
EXTENDED PURGE AD-4
™
AIR DRYER
STANDARD AD-4
™
AIR DRYER
LOWER
BRACKET
DESCRIPTION
The function of the AD-4
™
air dryer is to collect and remove
air system contaminants in solid, liquid and vapor form be-
fore 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-4
™
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, purge valve
mechanism, a cast-in heater element with a replaceable
thermostat assembly and three threaded air connections.
The three air connections are identified with embossed
numbers and lettering. The identification and function of each
is as follows:
Port l.D.
Function/Connection
CON 4 ................ Control Port
(from unloader port on governor).
SUP 11 .............. Supply Port (air in).
DEL 2 ................ Delivery Port (air out).
A cast-in heater element and replaceable thermostat with
an external terminal are provided.
The voltage and wattage requirements of the heater and
thermostat are shown with embossed numbers and letters
in the recess adjacent to the control port marked “CON.”
UPPER
BRACKET
LOWER
BRACKET
PURGE
EXHAUST
FIGURE 1 - AD-4
™
AIR DRYER MODELS
SUPPLY
PORT
THERMOSTAT
TERMINAL
SUPPLY
PORT
CONTROL
PORT
DELIVERY PORT
PURGE
EXHAUST
UPPER
BRACKET
