Owner manual

4
EXHAUST - BRAKE RELEASE
When the brake application is released, air pressure in the
service port of the AR-1
™
valve returns to the foot brake
valve and is exhausted. Air, from above the relay piston,
fl ows back through the cover to the exhaust diaphragm. The
diaphragm fl exes in response to the returning air, sealing
the service port and opening the exhaust in the cover.
With the exhaust diaphragm blocking the service port,
returning air fl ows out the open exhaust. As air pressure
is reduced above the relay piston, pressure beneath it lifts
the piston away from the exhaust valve and opens the
exhaust passage. Air from the antilock modulators and
brake actuators returns to the AR-1
™
valve and fl ows out
the open exhaust. (See Figure 5)
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 AR-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 AR-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.
OPERATION & LEAKAGE TESTS
OPERATION TEST
1. Apply and release the brakes several times and check
for prompt application and release at each wheel. If
prompt reaction is noted at some, but not all wheels, test
the AntiLock modulator between the AR-1
™
valve and
the brake actuator for proper operation. If a “sluggish”
FIGURE 5 - AR-1
™
VALVE EXHAUST - BRAKE RELEASE
RESERVOIR
BRAKE
ACTUATOR
SUPPLY PORT
EXHAUST
ANTILOCK
CONTROLLER
QUICK EXHAUST DIA.
SERVICE PORT
RELAY PISTON
DELIVERY PORT
INLET/EXH. VALVE
ANTILOCK
MODULATOR
EXHAUST