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.
Chevrolet Cobalt Service & Repair Manual. Precautions
1.
After disassembling power brake unit,
soak metal components in solvent.
2.
Use only alcohol on components containing
rubber. After components have been thoroughly cleaned and rinsed
in solvent, they should be washed again ...