FORD 2012 F-550 v.2 - Manual (Page 256)

If you use a rental trailer, follow the instructions that the rental agency
gives to you.
Do not attach safety chains to the bumper.
Trailer brakes
Electric brakes and manual, automatic or surge-type trailer brakes are
safe if installed properly and adjusted to the manufacturer’s
specifications. The trailer brakes must meet local and Federal
regulations.
WARNING: If you own a trailer with a hydraulic brake system,
do not connect the trailer’s hydraulic brake system directly to
your vehicle’s brake system. The vehicle’s brake system is only
designed to carry the appropriate amount of brake fluid for the vehicle
alone. Connecting a hydraulic trailer braking system could adversely
affect your vehicle’s braking performance, which could result in loss of
vehicle control, crash or serious injury.
The braking system of the tow vehicle is rated for operation at the
GVWR not GCWR.
Integrated trailer brake controller (if equipped)
Your vehicle may be equipped with a fully integrated electronic trailer
brake controller (TBC). When used properly, the TBC helps ensure
smooth and effective trailer braking by powering the trailer’s electric
brakes with a proportional output based on the towing vehicle’s brake
pressure.
The Ford TBC has been tested to be compatible with several major
brands of electric-over-hydraulic trailer brakes; contact your authorized
dealer for information on which brands can be used.
WARNING: The Ford TBC has been verified to be compatible
with trailers having electric-actuated drum brakes (one to four
axles) and some electric-over-hydraulic types, but not hydraulic surge
types. It is the responsibility of the customer to ensure that the trailer
brakes are adjusted appropriately, functioning normally and all electric
connections are properly made. Failure to do so may result in loss of
vehicle control, crash or serious injury.
Tires, Wheels and Loading
256
2012 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)