Buick Repair Questions? Ask a Mechanic for Answers ASAP
Hi Im David, thanks for visiting the site. if you do not see anything leaking under the car, get a light and look at the inside of each tire and make sure you don't see anything splashed on the inside of the tires. if you don't notice anything there then the master cylinder went bad on you.
if you see fluid it would be a line or hose to the caliper
its not normal to hear a bang when a master cylinder goes bad I agree. Im going to check any related bulletins, please standby
Does the pedal raise back up after it goes to the floor?
are you there?