IC Bus CE Series 2020, Operation And Maintenance Manual

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Operation
Air Brakes
WARNING
To prevent personal injury and / or death, or
damage to property, to prevent loss of vehicle
braking or control resulting in property damage,
personal injury or death, never operate the
vehicle when insufficient air pressure (less than
70 psi [483 kPa]) is indicated for either the primary
or secondary air system, or if a low-pressure
alarm is sounding and a warning indicator is
illuminated. The volume of air required to stop
the vehicle may be greater than that available.
Have the brake system checked and repaired
before returning the vehicle to service.
All air brake equipped vehicles have a split brake system. A split
system provides a way to stop the vehicle if a failure occurs in
either the primary or secondary brake system. If air pressure is
lost in one system, the remaining system continues to provide
braking action.
Even though there is braking capability for emergency stopping,
do not operate the vehicle when a failure is indicated, because
there may be no way of replenishing air pressure.
If vehicle has been parked for an extended period in cold
weather, always check to be sure all wheels are rolling free
(brakes are not frozen) when starting out.
Always clean
accumulated ice and snow from brake linkage.
If air pressure in either section of the split air brake system is
reduced to 57psi (393 kPa) the warning buzzer will sound and
a RED air pressure indicator on the Instrument Panel Gauge
Cluster glows. In addition, the air gauge(s) will indicate low air
pressure in at least one of the split systems.
The warning buzzer and RED air pressure indicator
automatically shut OFF when the air pressure in both systems
is sufficient (approximately 70 psi [483 kPa]) to operate the
vehicle.
If the RED air pressure indicator and buzzer do not shut OFF
after startup, check the air pressure gauge(s) and see if one or
more sections of the split system has low air pressure.
If the RED indicator, buzzer, and gauge indicate a loss of
pressure while driving, the vehicle will still have some braking
capability. Either one-half of the split system or the spring brake
system braking capability is retained. However, the distance
required to stop the vehicle will be increased.
Air Disc Brakes (0004JBZ, 0004JCC, 0004WEY, 0004WEZ)
The air disc brake system encompasses a floating caliper design
that is activated when air pressure is introduced into the system.
The air disc brake system works by converting air pressure into
braking force. When braking is applied, air will enter the brake
chamber, applying pressure to the diaphragm. The pressure
created activates the system causing the brake pads to contact
the rotor. When braking is released, the air pressure in the brake
chamber is released, exhausting the pressure on the diaphragm,
causing the brake pads to return to their neutral / non-braked
position.
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