Bendix Commercial Vehicle Systems AD-2 AIR DRYERS 7/04 - Manual (Page 6)

6
D. Reassembly
Reinstall the thermostat cover according to Figure
17. Take special care to assure the rubber spacer
and the gasket are correctly installed, to assure
proper operation.
8. Every 7200 hours; 200,000 miles or every 24 months,
change the desiccant cartridge.
NOTE: The desiccant change interval may vary from vehicle
to vehicle. Although typical desiccant cartridge life
is two years, many will perform adequately for three
to four years. In order to take maximum advantage
of desiccant life and assure that replacement
occurs only when necessary, it is important that
Serviceability Checks 1 - 7 be performed.
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS
TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the parking
brakes, and always block the wheels. Always wear
safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When working
in the engine compartment, the engine should be
shut off and the ignition key should be removed.
Where circumstances require that the engine be in
operation, EXTREME CAUTION should be used to
prevent personal injury resulting from contact with
moving, rotating, leaking, heated or electrically
charged components.
3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended
procedures. Use only the proper tools and observe
all precautions pertaining to use of those tools.
4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure from
all reservoirs before beginning ANY work on the
vehicle. If the vehicle is equipped with an AD-IS
™
air dryer system or a dryer reservoir module, be
sure to drain the purge reservoir.
5. Following the vehicle manufacturer’s recommended
procedures, deactivate the electrical system in a
manner that safely removes all electrical power from
the vehicle.
6. Never exceed manufacturer’s recommended
pressures.
7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove a
component or plug unless you are certain all system
pressure has been depleted.
8. Use only genuine Bendix ® replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent size,
type and strength as original equipment and be
designed specifically for such applications and
systems.
9. Components with stripped threads or damaged parts
should be replaced rather than repaired. Do not
attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored to
their proper operating condition.
REPLACING OR REBUILDING THE AD-1 ™ AND
AD-2 ™ AIR DRYER
GENERAL
If, after completing the routine serviceability tests, it has
been determined that one or more components of the air
dryer requires replacement or maintenance, refer to page
13 to ascertain the appropriate kit(s) needed. When rebuilding
or replacing components of the air dryer use only genuine
Bendix replacement parts or kits.
REMOVAL OF DESICCANT CARTRIDGE AD-1 ™ & AD-2 ™
AIR DRYER
CAUTION!
1. Loosen the air line to the control port of air dryer and
allow the trapped air to escape to atmosphere. After
the air escapes, remove the control line from the air
dryer.
2. Loosen the delivery line from the delivery port or outlet
of the air dryer. After the pressure drops, remove the
delivery line. Loosen the delivery check valve from this
port to relieve any trapped air above the desiccant plate
assembly. If the AD-1
™ air dryer has an external check
valve at the delivery port loosen it to relieve air pressure.
3. Disconnect the heater wire.
4. Remove any exhaust silencers or the exhaust check
valve cover from the base of the air dryer. Using a hex
socket and wrench, loosen the purge valve assembly
and allow any trapped air to escape. Slowly unscrew the
purge valve and remove it.
5. Check all ports to insure that air is not trapped in the air
dryer by powdered desiccant material.
Air Dryer End Cover Removal Procedure
Warning - The AD-2
™ air dryer cartridge contains a high
spring load. When replacing the AD-2 ™ air dryer cartridge or
performing any maintenance requiring end cover removal
follow the procedure outlined below.