One problem related to brake fluid leak has been reported for the 2008 Ford F-350. The most recently reported issues are listed below.
I was in my driveway and stepped on the brake pedal to put the truck in reverse and I heard a loud 'pop' which felt like the brake pedal broke and then it sank to the floor, I popped the hood and saw brake fluid dripping from the bottom of the brake master cylinder. This part---"switch assy - Ford part-sw6349 (9f924)" had blown out the plastic connector while the metal casing was still attached to the bottom of the master cylinder. This will leave you with no brakes. If it happened on the road in traffic it could be deadly.