In heavy, slow traffic northbound in right lane on i-93 south expressway in boston first saw "check braking systems" message, then engine quit and i had no brakes. was able to pull over to shoulder and stopped car with the emergency brake. aaa towed us to hotel, sentry ford in medford, ma took car from there to dealership service department. they informed me that the brake booster assembly was not covered, since car was about 4 mos. past warranty. total bill $1617.33. (does not include the cost of a 4 day rental car.) if i had not been in the right lane and in slow traffic, when the brakes failed, i would have been in very serious trouble. *tr