You can easily purge the booster with just a few pedal pushes without the engine rinning. This will give you a hard pedal also.
Don't touch the brake pedal after you stop. Rev the engine in park a few times, and again, remember not to touch the brake pedal. Let the car sit over night.
Next day: Lift the hood. Engine off. Grab the large hose from the booster and pull it off. Did you hear air escaping? Possible booster is fine. Keep the hose off. Start the engine. Do you feel good vacuum? Clogged/collapsed hose might not create enough vacuum for the booster. How tight was the plastic L shaped hose fitting, between the hose and/or the booster's rubber gasket? How tight is the other end of the hose to the A/C?