Dryer Module Operation; Air Dryer Operation; Charge Cycle - BENDIX DRM DRYER RESERVOIR MODULE Manual

DELIVERY
GOVERNOR
CHECK
VALVE
(OPEN)
UNLOADER
PORT
PURGE
INLET
CONTROL
PORT
CHANNEL
(IN)
TURBO
CUTOFF
VALVE
(OPEN)
PURGE
VALVE
(CLOSED)
FIGURE 2 - AD-IS ® AIR DRYER CHARGE CYCLE. DIAGRAM SHOWS PRESSURE PROTECTION VALVES A AND B OPEN, C & D CLOSED.
The removable purge valve assembly incorporates the purge
valve mechanism and a turbocharger cutoff feature that is
designed to prevent loss of engine "turbo" boost pressure
during the purge cycle of the AD-IS
serviceability, all replaceable assemblies can be replaced
without removal of the air dryer from its mounting on the
vehicle. Refer to Preventive Maintenance section.
DRM ™

DRYER MODULE OPERATION:

GENERAL
(Refer to Figure 2)
The DRM ™ dryer module is designed to receive compressed
air from the vehicle air compressor, clean and dry the air
using the AD-IS ® air dryer, deliver air to the vehicle's primary
2
SAFETY
SEE
VALVE
NOTE 1
PRIMARY
PORT
(PRI)
ENGINE
TURBO
COMPRESSOR
PRIMARY
RESERVOIR
® air dryer. For ease of
DESICCANT
BED
OIL
SEPARATOR
PRESSURE PROTECTION
VALVES
A
B C
AUXILIARY PORTS
(TO ACCESSORIES)
reservoir, secondary reservoir and accessories, and control
the compressor/dryer charge cycle.
AIR DRYER OPERATION: GENERAL
®
The AD-IS air dryer alternates between two operational
modes or "cycles" during operation: the Charge Cycle and
the Purge Cycle. The following descriptions are separated
into these "cycles" of operation.

CHARGE CYCLE

When the compressor is loaded (compressing air)
compressed air, along with oil, oil vapor, water and water
PURGE
PURGE
ORIFICE
RESERVOIR
D
PURGE
RESERVOIR
DRAIN VALVE
Note 1:
®
The AD-IS air dryer purge piston has a
purge control channel drain. This allows
any condensation in this area to flow
past a diaphragm in the top of the purge
piston and out through a channel in the
middle of the central bolt of the purge
assembly to be drained. During the
purge cycle this drain is closed.
(Refer to Figure 2)
SECONDARY
RESERVOIR