Pontiac 2008 G6 - Manual (Page 280)

Brake Wear
Your vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched warning
sound when the brake pads are worn and new pads
are needed. The sound can come and go or be heard all
the time your vehicle is moving, except when you are
pushing on the brake pedal firmly.
{ CAUTION:
The brake wear warning sound means that soon
the brakes will not work well. That could lead to
an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
Notice: Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can cause a brake
squeal when the brakes are first applied or lightly applied.
This does not mean something is wrong with the brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to torque specifications in
Capacities and Specifications on page 5-119.
Brake linings should always be replaced as complete
axle sets.
Brake Pedal Travel
See your dealer/retailer 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
might be required.
Brake Adjustment
Every time you apply the brakes, with or without the
vehicle moving, the brakes adjust for wear.
5-44