Left Home base for the 6 hr trip to NJMP at 6:00 am 30 minutes later smoke was rolling out of the right frt wheel of the trailer duals. Pulled the wheel off limped into co SCCA racer Steve Moores Garage (Won the f500 Sunday) proceeded with repairs. New Backing plate with complete brake assembly new hub assembly with bearings not quit as simple as it sounds when the first hub was incorrect spacing on wheel studs(New rule always try hub on wheel first) measure studs add 1/4" on to new jersey arriving 9:30pm at least the rest of the weekend was good! Now what the hell caused the brake to set up? Fauilure of the magnet any way to test the wheel bearings had been greased. and now back home we have pulled the rest of the wheels off and all appear fine good lining plenty of grease etc. Just glad it happened where it did and not on the turnpike. Any suggestions as to how check magnets so no reoccurence!!