FORD 2009 F-550 v.1 - Manual (Page 264)

WARNING: Do not adjust a weight distributing hitch to any
position where the rear bumper of the vehicle is higher than it
was before attaching the trailer. Doing so will defeat the function of
the weight distributing hitch, which may cause unpredictable handling,
and could result in serious personal injury.
Safety chains
Always connect the trailer’s safety chains to the frame or hook retainers
of the vehicle hitch. To connect the trailer’s safety chains, cross the
chains under the trailer tongue and allow slack for turning corners.
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.
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.
WARNING: The Ford TBC has only been verified to be
compatible with trailers having electric-actuated drum brakes
(one to four axles) and not hydraulic surge or electric-over-hydraulic
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.
2009 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)
Tires, Wheels and Loading
264