Faulty truck brakes bring grave consequences. Thus, American courts place strong incentives on truck owners to ensure brakes are in working order. California law, for example, prevents a truck owners from delegating the duty to maintain brakes. Louisiana has even gone so far to find trucking companies strictly liable for brake defects. If, however, brake failure is caused by a mechanics error the truck owner may be insulated from liability.
All states require brakes to be kept in good working order. Generally speaking, violating such a state statute will constitute negligence per se. (See above).