Bendix Commercial Vehicle Systems AD-IS AIR DRYER AND RESERVOIR SYSTM - Manual (Page 3)

3
DESCRIPTION
The function of both the Bendix ® AD-IS ® (Integrated Solution
Air Dryer) air dryer and reservoir system and the Bendix ®
AD-IS ® PuraGuard ® oil coalescing air dryer and reservoir
system is to collect and remove air system contaminants
in solid, liquid and aerosol form before they enter the brake
system and to provide—as a module—heavy vehicles with
an integrated vehicle air dryer, purge reservoir, governor
and a number of the charging valve components in a
module. These components have been designed as an
integrated air supply system.
Both air dryer and reservoir systems provide clean, dry air
to the components of the brake system which increases
the life of the system and reduces maintenance costs.
The necessity for daily manual draining of the reservoirs
is eliminated.
The Bendix AD-IS PuraGuard oil coalescing air dryer has
an identical appearance to the standard Bendix AD-IS air
dryer, but contains a coalescing media at the inlet of the
desiccant bed. The coalescing media provides a higher
level of oil removal over the standard AD-IS air dryer.
The AD-IS PuraGuard oil coalescing air dryer has all of
the same functions as the standard AD-IS air dryer and is
used in applications where lower oil concentration levels
are required.
IMPORTANT: When servicing, note that standard AD-IS
air dryers or air dryer cartridges may be serviced with
PuraGuard oil coalescing air dryers or cartridges, however,
PuraGuard oil coalescing air dryers or cartridges must only
be serviced with like replacements.
Note: Unless otherwise stated in this manual, AD-IS air
dryer and reservoir systems refers to both the standard and
PuraGuard oil coalescing air dryer and reservoir systems.
The function of the pressure protection valves is to protect
each reservoir from a pressure loss in the other reservoir or
a pressure loss in an air accessory. Each of the pressure
protection valves in the AD-IS air dryer and reservoir
systems may have different pressure settings. These are
factory set and must not be changed or adjusted.
The air dryer and reservoir system consists of a “spin on”
desiccant cartridge secured to a base assembly. The
base assembly contains a delivery check valve assembly,
safety valve, heater and thermostat assembly, pressure
protection valves, threaded air connections and the purge
valve assembly.
TABLE 1 - PORT DESIGNATIONS
Air Connection
Port ID
Function/
Connection
QTY
1
IN
Inlet Port (air in) 1
21
PRI
Delivery Port Out (to Primary Reservoir) 1
22
SEC
Delivery Port out (to Secondary Reservoir) 1
24
AUX 1
Auxiliary Delivery Port (air out) 4
23
AUX 2
Auxiliary Delivery Port (air out) 1
UNL Unloader Control Air (D-2A ™ Governor) 2
RES Common Reservoir Pressure (D-2A ™ Governor) 2
EXH Governor Exhaust 1
The removable purge valve assembly incorporates the
purge valve mechanism and a turbocharger cut-off feature
that is designed to prevent loss of engine “turbo” boost
pressure during the purge cycle of the Bendix ® AD-IS ® air
dryer and reservoir system. For ease of maintenance, all
replaceable assemblies can be serviced without removal
of the air dryer and reservoir system from its mounting on
the vehicle. Refer to Preventive Maintenance section.
BENDIX AD-IS AIR DRYER AND RESERVOIR
SYSTEM OPERATION: GENERAL
(Refer to Figure 2.)
The Bendix AD-IS air dryer and reservoir systems are
designed to receive compressed air from the vehicle air
compressor, clean and dry the air, deliver air to the vehicle’s
primary reservoir, secondary reservoir and accessories,
and control the compressor/dryer charge cycle.
The AD-IS air dryer and reservoir system alternates
between two modes or “cycles” during operation: the
Charge Cycle and the Purge Cycle. The following describes
these “cycles” of operation.