Bendix Commercial Vehicle Systems AD-RP PuraGuard Oil Coalescing Remote Purge Air Dryers - Manual (Page 11)

11
RETROFITTING THE BENDIX ® AD-RP ™ AIR
DRYER
GENERAL
The following retrofit instructions are presented for
reference purposes only. Bendix
® replacement air dryers
are packaged with the most up-to-date installation
instructions. The instructions packaged with the Bendix
®
AD-RP ™ air dryer should be followed instead of those
presented here. The preceding portion of this manual
deals with "in-service" repair and/or replacement of
the AD-RP air dryer. This portion of the manual is
concerned with installing an AD-RP air dryer on a
vehicle not previously equipped with one.
VEHICLE APPLICATION REQUIREMENTS
The basic application requirements presented here apply
to a standard air dryer installation. The majority of highway
vehicles in use today will meet these basic requirements,
however some may not. Examples of vehicles that may
not meet the requirements include refuse trucks, city
coaches, bulk trailer unloading operations and other high
air consumption systems. While the AD-RP air dryer can be
used on these vehicles, the standard installation procedure
presented in this manual may require modifi cation to
ensure proper operation and service life. Consult your local
authorized Bendix parts outlet or sales representative for
additional information.
1. Charge Cycle Time - The AD-RP air dryer is designed
to provide clean, dry air for the brake system. When a
vehicle's air system is used to operate non-brake air
accessories it is necessary to determine that — during
normal, daily operation — the compressor should
recover from governor "cut-in" to governor "cut-out"
(usually 110 psi to 130 psi) in 90 seconds or less at
engine RPMs commensurate with the vehicle vocation.
Note: The Bendix AD-RP air dryer must be used in
conjunction with governors which have a 120 to 130 psi
nominal cut-out pressure. If a governor is used that is
not within this limitation, contact your Bendix parts outlet
or sales representative for additional information. If the
recovery time consistently exceeds this limit, it may be
necessary to "by-pass" the air accessory responsible
for the high air usage.
2. Purge Cycle Time - During normal vehicle operation, the
air compressor must remain unloaded for a minimum
of 30 seconds. This minimum purge time is required
to ensure complete regeneration of the desiccant
material. If the purge time is occasionally shorter than
the times specifi ed, no permanent ill effect should be
expected. If the purge time is consistently less than
the minimum, however, an accessory by-pass system
must be installed.
3. European Air Brake Systems - The AD-RP air dryer
must not be installed in brake systems that incorporate
compressors without integral unloading mechanisms
and/or utilize a compressor discharge line unloader
valve. When vehicles of this type are encountered,
other Bendix air dryer models must be used. Consult
your local authorized Bendix parts outlet or sales
representative for additional information.
4. Air Compressor Size - The AD-RP air dryer was
designed primarily for use with compressors rated up
to 30 CFM. Contact and authorized Bendix parts outlet
or a Bendix sales representative for assistance when
using the AD-RP dryer with a compressor which has a
rated displacement exceeding 30 CFM.
5. Holset "E or QE" Type Air Compressors - The AD-RP
dryer can be installed with the Holset Type "E or QE"
compressor. When the AD-RP air dryer is used in this
installation, the Holset ECON valve should be removed
and the special orifi ce check valve in the "make-up" line
should be removed and replaced with a conventional
single check valve.
6. Use the following guidelines to determine the vehicle
application suitable for the Bendix AD-RP air dryer:
Total Vehicle
Reservoir Volume
Requirement
Less than
12,500 cu. in.
Bendix ® AD-RP ™ Air Dryer
(use kit part no. 5008972)
Greater than
12,500 cu. in.
Contact Bendix Commercial Vehicle
Systems LLC.