Bendix Commercial Vehicle Systems ATR-1 ANTILOCK TRACTION RELAY 02/11 - Manual (Page 5)

5
speed up to 25 mph, the antilock traction controller instantly
energizes the solenoid in the ATR-1
™ valve which then
applies air to each of the rear axle modulators as shown
in Figure 8. The modulators are equipped with solenoid
valves also and because they are also controlled by the
controller, the solenoid valves in the appropriate modulator
are opened and closed to gently pump the brake on the
spinning wheel only. This brake application, to the spinning
wheel, forces the differential to drive the stationary or slowly
spinning wheel.
OPERATION
Reservoir air pressure is constantly present at the traction
solenoid. When the electronic controller detects wheel
spin it energizes the solenoid and in response the solenoid
opens momentarily. While the solenoid is open, air is
delivered through internal passages to the double check
valve. The check valve diaphragm fl exes in response and
seals the passage to the open exhaust of the brake valve.
Once past the double check valve, air from the solenoid
fl ows through the rest of the valve in the same manner as
a normal service brake application and air is delivered out
the delivery ports of the ATR-1
™ valve.
When the electronic controller de-energizes the solenoid,
air between the solenoid and the double check valve
returns to the solenoid and is exhausted. Air between the
relay piston and double check valve is exhausted at the
brake valve while delivery pressure is exhausted at the
main ATR-1
™ valve’s exhaust port.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before
performing any intrusive maintenance procedures.
An extended warranty may be voided if intrusive
maintenance is performed during this period.
Because no two vehicles operate under identical conditions,
maintenance intervals will vary. Experience is a valuable
guide in determining the best maintenance interval for a
vehicle.
GENERAL
Perform the tests and inspections presented at the
prescribed intervals. If the ATR-1
™ valve fails to function
as described, or leakage is excessive, it should be repaired
or replaced with a new or genuine Bendix remanufactured
unit, available at any authorized parts outlet.
EVERY 3 MONTHS, 25,000 MILES
OR 900 OPERATING HOURS
1. Remove any accumulated contaminates and visually
inspect the exterior for excessive corrosion and physical
damage.
2. Inspect all air lines connected to the ATR-1 ™ valve
for signs of wear or physical damage. Replace as
necessary.
3. Test air line fi ttings for excessive leakage and tighten
or replace as necessary.
4. Perform the Leakage Test described in this manual.
EVERY YEAR, 100,000 MILES, OR
3,600 OPERATING HOURS
1. Perform the Operation and Leakage Tests described
in this manual.
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 a
Bendix
® 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.