GM Service Manual Online
For 1990-2009 cars only

It is recommended that the propshaft-mounted parking brake be burnished as part of the new vehicle break-in. The parking brake will work best after it has been burnished following these instructions:

Make 10 stops, using the parking brake hand lever or foot pedal, from 20 mph (32 km/h) about 2 1/2 miles (4 km) apart. Between stops, drive the vehicle at 20 mph (32 km/h) to allow the brake to cool.

Caution: Driving with the parking brake on can damage the transmission and brake system parts. Verify that the parking brake is fully released and the brake warning light is off before driving.