Bendix Commercial Vehicle Systems ATR-3 ANTILOCK TRAC RELAY VLV - Manual (Page 7)

7
5. Test valve as outlined in Operational and Leakage
Tests.
OPERATIONAL AND LEAKAGE TESTS
1. Chock the wheels, fully charge air brake system and
adjust the brakes.
2. Make several brake applications and check for prompt
application and release at each wheel.
3. Check for inlet valve and O-ring leakage. Make this
check with the service brakes released. Coat the
exhaust port and the area around the retaining ring
with a soap solution; leakage of a one-inch bubble in
3 seconds is permitted.
4. Check for exhaust valve leakage. Make this check with
the service brakes fully applied. Coat the outside of
the valve where the cover joins the body to check for
seal ring leakage; no leakage is permitted.
If the valve does not function as described above, or if the
leakage is excessive, it is recommended that the valve be
replaced with new or remanufactured units or repaired with
genuine Bendix parts, available at any authorized Bendix
parts outlet.
Refer to the Antilock Traction Controller Service Data sheet
for operational test for traction functionality.
GENERAL
A change in vehicle braking characteristics or a low
pressure warning may indicate a malfunction in one or
the other brake circuit, and although the vehicle air brake
system may continue to function, the vehicle should not
be operated until the necessary repairs have been made
and both braking circuits, including the pneumatic and
mechanical devices, are operating normally. Always
check the vehicle brake system for proper operation after
performing brake work and before returning the vehicle
to service.
OPERATION TEST
1. Apply and release the brakes several times and check
for prompt application and release at each wheel.
If an incomplete or sluggish release of the brakes is
noted at some, but not all wheels, test the Antilock
Modulator Valve(s) operating those wheels for proper
operation, and inspect for kinked or obstructed air hose
leading to, or from, the Modulator(s).
If an incomplete or sluggish release is noted at all
wheels, inspect for kinked or obstructed air hose
leading to, or from, the ATR-6
™ valve.
Note: The ATR-6 ™ valve’s Crack Pressure differential can
be checked by applying 10 psi to the service port and noting
the pressure registered at the delivery port with a gauge
of known accuracy. Subtract the delivery port pressure
from the 10 psi service pressure to obtain the differential.
Compare the measured differential with the Crack Pressure
BENDIX TECHNICAL ASSISTANCE TEAM
For direct telephone technical support, call the Bendix
Tech Team at:
1-800-AIR-BRAKE (1-800-247-2725),
Monday through Friday, 8:00 A.M. to 6:00 P.M. EST,
and follow the instructions in the recorded message.
Or, you may e-mail: [email protected]
specifi ed for the ATR-6 ™ valve’s part number (also shown
on the I.D. washer installed on one of the cap screws).
NOTE: For ATR-6
™ valves not incorporating a relay piston
return spring (13), the measured differential should be
approximately 4 psi. When a spring is in use, the differential
will be higher.
2. Disconnect the ATR-6 ™ valve’s two pin solenoid
connector from the Controller wire harness. Apply the
probes of a volt-ohm meter to the connector leading
to the solenoid and note the resistance of the solenoid
is between 15 and 17 ohms. If resistance other than
this is found, replace the ATR-6
™ valve.
3. Apply and remove vehicle power (12 VDC) to the
two pin connector half leading to the ATR-6 ™ valve’s
(solenoid) while observing the brake chambers. Note
that a brake application is made and held while power
is applied to the ATR-6
™ valve’s solenoid and that it is
released when power is removed.
LEAKAGE TESTS
1. Build the air system pressure to governor cutout. Apply
a soap solution to the exhaust port. The leakage noted
should not exceed a one-inch bubble in less than 3
seconds.
2. Make and hold a full brake application and apply a soap
solution to the exhaust port and around the cover where
it joins the body. The leakage noted should not exceed
a one-inch bubble in less than 3 seconds at the exhaust
port. If the ATR-6
™ valve fails to function as described,
or leakage is excessive, it should be replaced with a
new or genuine Bendix unit.