WARNING:
Do not drive or continue to drive if the low air pressure buzzer is sounding or the brake warning light is lit. These warnings indicate that air pressure is not to normal operating level. Continued use of the vehicle could result in loss of braking ability.
WARNING:
Avoid repeated light application of the brake pedal. This depletes air pressure faster and could result in loss of braking capability.
WARNING:
Do not move the vehicle when the air pressure is insufficient because the brake system may be inoperative. |
After starting the engine, give the air compressor time to build up the air pressure to
60 psi (414 kPa) before moving your vehicle.
Periodically check the air pressure gauge while driving. Pressure should range between approximately
100 psi (690 kPa) to
130 psi (896 kPa). The air compressor governor cut-in and cutout pressure settings are set at the factory and are not adjustable.
When air pressure is insufficient (below
60 psi (414 kPa)), a warning light illuminates and a buzzer sounds when the ignition is in the on position. This may happen because excessive brake applications are depleting the system air pressure. If this condition occurs, stop driving your vehicle until the compressor has fully recharged the air system.
Select a gear ratio to help slow your vehicle before descending grades. Supplementing with brakes, as required, help to safely slow the vehicle and avoids overspeeding the engine.
Air Chamber Stroke Indication
Air chamber push rods have orange stroke indicator markers that warn when the braking system requires adjustment or repair. The painted orange indicator is on the air chamber push rod at the slack adjuster stroke dimension that requires service when visible during brake application.
A qualified service technician should perform air brake inspection and adjustment or repairs keeping to the instructions in the service manual.
Cam Brakes - Automatic Slack Adjusters
WARNING:
Do not manually adjust the automatic slack adjusters to correct excessive push rod stroke as it may result in reduced brake effectiveness and a vehicle crash. Excessive push rod stroke indicates that a problem exists with the automatic adjuster, with the installation of the adjuster, or with foundation brake components that manual adjustment does not remedy. Seek service from a qualified facility for excessive push rod stroke. |
Standard air brakes (cam) are equipped with automatic brake adjusters. Automatic adjustment occurs during brake applications. Inspect brakes for proper adjustment at the specified intervals. See
Scheduled Maintenance.
Emergency Air Brake
WARNING:
Do not continue to operate the vehicle with a failure of one of the brake systems. Take the vehicle to your dealer for service immediately. |
All vehicles are equipped with a dual brake system. In the unlikely event of a failure of one system, the second system functions for emergency stopping. The brake pedal controls all these systems in the same manner as for normal stops.