Ford 2007 F-650 Owner's Manual page 238

AIR BRAKE ADJUSTMENT
Failure to maintain proper air brake adjustment can result in
reduction or loss of braking ability.
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
Inspect standard air brakes equipped with automatic slack adjusters for
proper brake adjustment every four months or 20,000 miles (32,000 km)
whichever occurs first.
However, more frequent inspection is required if your vehicle's brakes
are subjected to heavy use or adverse operating conditions such as:
• Frequent brake applications while fully loaded.
• Operation on hilly or mountainous terrain.
• Frequent operation on dirt, gravel or mud.
Some aftermarket brake linings also require more frequent inspections.
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.
2007 F-650/750 (f67)
Supplement
USA (fus)
Scheduled Maintenance Guide
237