Do not pump the brakes. Just hold the brake pedal down firmly and let antilock work. A slight brake pedal pulsation might be felt or some noise noticed, but this is normal.
Antilock Brake System (ABS)
Braking in EmergenciesChevrolet Cobalt Service & Repair Manual. Motor Vehicle, Inspection
A visual inspection must always
be performed to confirm the presence of aftermarket components, potential
collision damage, or areas of concern.
1.
Inspect service history of vehicle.
2.
Inspect engine oil level.
...