Bendix Commercial Vehicle Systems AD-IS EVERFLOW ASSEMBLY - Manual (Page 5)

5
WARNING!
This air dryer is intended to remove moisture and other
contaminants normally found in the air brake system. Do
not inject alcohol, anti-freeze, or other de-icing substances
into or upstream of the air dryer. Alcohol is removed by
the dryer, and reduces the effectiveness of the device to
dry air. Use of these or other substances can damage the
air dryer and will void the warranty.
OPERATION & LEAKAGE TESTS
(For additional information order "Air Leakage Video"
BW2327)
1. Check all lines and fi ttings leading to and from the air
dryer for leakage and integrity. Repair any leaks found.
2. Build up system pressure to governor cut-out and note
that the AD-IS ® air dryer purges with an audible escape
of air. Watch the system pressure for leakage for a ten
minute period. If pressure drop exceeds, for a single
vehicle - 1 psi/minute from either service reservoir; or for
tractor trailer - 3 psi/minute from either service reservoir,
inspect the vehicle air systems for sources of leakage
and repair them.
3. Caution: Be sure to wear safety glasses in case of a
purge blast. Check for excessive leakage around the
purge valve of the dryer, not in the purge cycle, with
the compressor in the loaded mode (compressing air).
Apply a soap solution to the purge valve exhaust port and
observe that leakage does not exceed a 1” bubble in 1
second. If the leakage exceeds the maximum specifi ed,
refer to section entitled Troubleshooting, Symptom 4.
4. Build up system pressure to governor cut-out and note
that one of the AD-IS ® EverFlow ™ assembly dryers
purges with an audible burst of air, followed immediately
by approximately 30 seconds of air fl owing out of the
purge valve. “Fan” the service brakes to reduce system
air pressure to governor cut-in. Note that the system
once again builds to full pressure and is followed by
the AD-IS
® EverFlow ™ assembly other air dryer purge.
If system does not follow this pattern, refer to section
entitled Troubleshooting, Symptoms 1, 2 and 3. Check
the operation of the end cover heater and thermostat
assembly during cold weather operation as follows:
A. Electric Power to the Dryer NOTE: The EverFlow ™
assembly should be wired through the ignition and not
the battery. With the ignition or engine kill switch in
the RUN position, check for voltage to the heater and
thermostat assembly using a voltmeter or test light.
Unplug the electrical connector at the air dryer and
place the test leads on each of the connections of the
female connector on the vehicle power lead. If there
is no voltage, look for a blown fuse, broken wires, or
corrosion in the vehicle wiring harness. Check to see
if a good ground path exists. The EverFlow
™ assembly
requires the correct electrical voltage to operate
properly.
B. Thermostat and Heater Operation (Refer to Figure
3). NOTE: These tests can only be conducted during
cold weather operation. Turn off the ignition switch
and cool the thermostat and heater assembly to below
40 degrees Fahrenheit. Using an ohmmeter, check
the resistance between the electrical pins in the air
dryer connector half. The resistance should be 1.5 to
3.0 ohms for the 12 volt heater assembly and 6.0 to
9.0 ohms for the 24 volt heater assembly. Warm the
thermostat and heater assembly to approximately 90
degrees Fahrenheit and again check the resistance.
The resistance should exceed 1000 ohms. If the
resistance values obtained are within the stated limits,
the thermostat and heater assembly is operating
properly. If the resistance values obtained are outside
the stated limits, replace the heater and thermostat
assembly.
REBUILDING THE AD-IS ® AIR DRYER
GENERAL SAFETY GUIDELINES
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
FIGURE 3 - AD-IS ® AIR DRYER HEATER AND
THERMOSTAT CONNECTOR
HEATER & THERMOSTAT
CONNECTOR