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. Component Replacement
Master Cylinder
1.
On Vibe models, remove air filter
hose clamp and hose from throttle body.
2.
On all models, disconnect fluid
level sensor retainer and electrical connector.
3.
Drain master cylinder ...