One problem related to brake drum has been reported for the 1999 Ford F-150. The most recently reported issues are listed below.
While braking at any speed vibration occurred in vehicle, more noticeable when there was a load in truck. Dealership examined vehicle over 10 times and found that a dust/powder was accumulating inside brake drum. Dealership informed consumer there was no effective remedy for this problem. Consumer states on four occasions the vibrations caused the rear wheels to lock and then the pedal went soft with no braking power.