Ford 2007 F-650 Owner's Manual page 106

Air chamber stroke indication
Air chamber push rods have orange stroke indicator markers that warn
when the braking system requires adjustment or repair. The orange
stripe is painted on the air chamber push rod at the slack adjuster stroke
dimension which requires service when visible during brake application.
Air brake inspection and adjustment or repairs should be performed by a
qualified service technician in accordance with the instructions in the
service manual.
Cam brakes - automatic slack adjusters
Standard air brakes (cam) are
equipped with automatic brake
adjusters. Automatic adjustment
occurs during brake applications.
Inspect brakes for proper
adjustment at the intervals listed in
the Scheduled Maintenance Guide
chapter.
Do not manually adjust the
automatic slack adjusters to
correct excessive pushrod stroke
as it may result in reduced brake
effectiveness and a vehicle crash.
Excessive pushrod stroke
indicates that a problem exists
with the automatic adjuster, with
the installation of the adjuster, or
with foundation brake components
that manual adjustment will not
remedy. Seek service from a
qualified facility for excessive
pushrod stroke.
Emergency air brake
All vehicles are equipped with a dual brake system. In the unlikely event
of a failure of one system, the second system will function for emergency
stopping. These systems are all controlled by the brake pedal in the
same manner as for normal stops.
2007 F-650/750 (f67)
Supplement
USA (fus)
Driving
105