GMC TopKick 2007 Owner's Manual page 297

Four-Wheel Disc Brakes
(Hydraulic Only)
Your vehicle has four-wheel disc brakes.
Some driving conditions or climates may cause a
brake squeal when the brakes are first applied
or lightly applied. This does not mean something
is wrong with the brakes.
Brake linings should always be replaced as
complete axle sets.
Four-Wheel and Six-Wheel Drum
Brakes (Air Only)
The brake drums should be removed and inspected
each time the tires are removed for rotation or
changing. When you have the front brakes
replaced, have the rear brakes inspected, too.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return
to normal height, or if there is a rapid increase
in pedal travel. This could be a sign that
brake service is needed.
Brake Adjustment
Every time you make a brake stop, the brakes
adjust for wear.
Brake Adjustment on Air Braked
Vehicles
Your vehicle has automatic slack adjusters.
Every time you make a brake stop, the brakes
automatically adjust for wear. Slack adjusters
should never be manually adjusted to correct
excessive brake chamber pushrod stroke.
Excessive brake chamber pushrod stroke means
that the brake system needs to be serviced by
a qualified service technician.
Notice: Do not manually adjust automatic slack
adjusters. Manual adjustment of the automatic
slack adjusters can result in a degradation of
the slack adjuster performance over time.
If the brake chamber pushrod stroke is out of
adjustment, the brake system needs to be
serviced by a qualified service technician.
297