See also:

Using ABS
Do not pump the brakes. Just hold the brake pedal down firmly and let ABS work. You might hear the ABS pump or motor operating and feel the brake pedal pulsate, but this is normal. ...

Reporting Safety Defects to General Motors
In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors. Call 1-800-521-7300, or write: Buick Customer Assistance Center P.O. Box 33136 Detroi ...

When to Inspect the Engine Air Cleaner/Filter
Inspect the air cleaner/filter at the scheduled maintenance intervals and replace it at the first oil change after each 80 000 km (50,000 mi) interval. See Maintenance Schedule  for more info ...