2008 FORD SUPER DUTY brake

GVWR (Gross Vehicle Weight
Rating)– is the maximum
allowable weight of the fully loaded
vehicle (including all options,
equipment, passengers and cargo).
The GVWR is shown on the
Safety Compliance Certification
Label located on the B-Pillar or
the edge of the driver’s door.
The GVW must never exceed the
GVWR.
GCW (Gross Combined Weight)– is the weight of the loaded vehicle
(GVW) plus the weight of the fully loaded trailer.
GCWR (Gross Combined Weight Rating)– is the maximum allowable
weight of the vehicle and the loaded trailer – including all cargo and
passengers – that the vehicle can handle without risking damage.
(Important: The towing vehicles’ braking system is rated for operation at
GVWR, not at GCWR. Separate functional brakes should be used for safe
control of towed vehicles and for trailers where the GCW of the towing
vehicle plus the trailer exceed the GVWR of the towing vehicle.The
GCW must never exceed the GCWR.
Maximum Loaded Trailer Weight– is the highest possible weight of a
fully loaded trailer the vehicle can tow. It assumes a vehicle with only
mandatory options, no cargo (internal or external), a tongue load of
10–15% (conventional trailer) or king pin weight of 15–25% (fifth wheel
trailer), and driver only (150 lb. [68 kg]).Consult your authorized
dealer (or theRV and Trailer Towing Guideprovided by your
authorized dealer) for more detailed information.
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Loaded vehicles may handle differently than unloaded vehicles.
Extra precautions, such as slower speeds and increased stopping
distance, should be taken when driving a heavily loaded vehicle.
Your vehicle can haul more cargo and people than most passenger cars.
Depending upon the type and placement of the load, hauling cargo and
people may raise the center of gravity of the vehicle.
TRAILER TOWING
Note:The trailer towing charts in this section apply to vehicles equipped
with gasoline engines; for vehicles equipped with diesel engines, refer to
your6.0/6.4 Liter Power Stroke Direct Injection Turbo Diesel Owner’s
Guide Supplement.
Your vehicle may tow a Conventional/Class IV trailer or fifth wheel trailer
provided the maximum trailer weight is less than or equal to the
maximum trailer weight listed for your engine and rear axle ratio on the
following charts.
To calculate your maximum trailer weight:
For pickup trucks:Take curb weight, hitch hardware and the driver’s
weight, then subtract them from the GCWR listed for your vehicle series,
engine, transmission and drive axle ratio(refer to the chart/table in the
following text). This calculation will give you the maximum trailer
weight possible for your vehicle.
For chassis cabs and pickup trucks with aftermarket equipment:
Weigh your vehicle at a certified scale and subtract this actual curb
weight, hitch hardware, and the driver’s weight from the GCWR listed for
your vehicle series, engine, transmission and drive axle ratio(refer to
the chart/table in the following text). This calculation will give you the
maximum trailer weight possible for your vehicle.
The weight of all additional cargo and passengers must be subtracted
from the maximum trailer weight calculated above.
Further trailer/hitch restrictions and limitations exist depending on the
type of trailer and hitch used. These additional maximum trailer weight
and tongue load limitations are listed in the chart/table that follows the
listing of GCWRs.
Towing a trailer places an additional load on your vehicle’s engine,
transmission, axle, brakes, tires and suspension. Inspect these
components carefully prior to and after any towing operation. Refer to
Transmission fluid temperature gaugein theInstrument Cluster
chapter for the transmission fluid temperature information.
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Note:Adjusting a weight distributing hitch so the rear bumper of the
vehicle is higher than it was unloaded will defeat the function of the
weight distributing hitch and may cause unpredictable handling.
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.
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.
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.
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The TBC user interface consists of
the following:
1.+/- (GAIN adjustment
buttons):Pressing these buttons
will adjust the TBC’s power output
to the trailer brakes (in 0.5
increments). The GAIN setting can
be increased to a maximum of 10.0
or decreased to a minimum of 0 (no
trailer braking). Pressing and
holding a button will raise or lower
the setting continuously.
2.Trailer connection indicator:This lamp indicates trailer electrical
connection status.
•When a successful trailer connection is detected, the indicator will be
green.
•If the electrical connection is lost, the indicator will flash red. If the
connection is lost while the vehicle is stationary, the indicator will turn
off after 30 seconds. If the connection is lost while the vehicle is
moving, the indicator will flash until the ignition is turned off, then on
again or if there is a reconnection.
•If no electrical connection is detected after the ignition is turned on,
pressing a GAIN adjustment button will display the GAIN setting.
Sliding the manual control will display the GAIN setting, OUTPUT bar
graph and light the trailer indicator red.
3.GAIN setting display:Shows the current GAIN setting. This will
illuminate when a trailer is connected, flash if the trailer becomes
disconnected, or remain off if no trailer is connected.
4.OUTPUT bar graph:When the vehicle’s brake pedal is pushed, or
when the manual control is activated, green bar indicators will illuminate
to indicate the amount of power going to the trailer brakes relative to
the brake pedal or manual control input.
5.Manual control lever:Slide the control lever to the left to activate
power to the trailer’s electric brakes independent of the tow vehicle’s
brakes (see the followingProcedure for adjusting GAINsection for
instructions on proper use of this feature). If the manual control is
activated while the brake is also applied, the greater of the two inputs
determines the power sent to the trailer brakes.
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•Stop Lamps:Activating the TBC manual control lever will illuminate
both the trailer brake lamps and the tow vehicle brake lamps except
the Center High-Mount Stop Lamp (presuming proper trailer electrical
connection). Pressing the vehicle brake pedal will also illuminate both
trailer and vehicle brake lamps.
GAIN
The GAIN setting is used to set the TBC for the specific towing
condition and should be changed as towing conditions change. Changes
to towing conditions include trailer load, vehicle load, road conditions
and weather.
The GAIN should be set to provide the maximum trailer braking
assistance while ensuring the trailer wheels do not lock when braking.
Locked trailer wheels may lead to trailer instability.
Procedure for adjusting GAIN:
Note:This should only be performed in a traffic free environment at
speeds of approximately 20 – 25 mph (30 – 40 km/h).
1. Make sure the trailer brakes are in good working condition,
functioning normally, and properly adjusted. See your trailer dealer if
necessary.
2. Hook-up the trailer and make the electrical connections according to
the trailer manufacturer’s instructions.
3. When a trailer with electric brakes is plugged in, the trailer connection
indicator will illuminate green on the TBC and the GAIN setting display
will illuminate.
4. Use the GAIN adjustment (+/-) buttons to increase or decrease the
GAIN setting to the desired starting point. (A GAIN setting of 6.0 is a
good starting point for heavier loads.)
5. In a traffic-free environment, tow the trailer on a dry, level surface at
a speed of 20 – 25 mph (30 – 40 km/h) and squeeze the manual control
lever completely.
6. If the trailer wheels lock-up (indicated by squealing tires), reduce the
GAIN setting; if the trailer wheels turn freely, increase the GAIN setting.
Repeat Steps 5 and 6 until the GAIN setting is at a point just below
trailer wheel lock-up. If towing a heavier trailer, trailer wheel lockup may
not be attainable even with the maximum GAIN setting of 10.
Explanation of instrument cluster messages:
The TBC interacts with the instrument cluster message center. These
messages, accompanied by a single chime, will be displayed when the
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TBC determines a malfunction in the trailer connection, TBC system, or
in the trailer. These messages are listed below:
TRAILER DISCONNECTED (if equipped with message center) or
CHECK TRAILER (if equipped with mini message center):This
message is displayed when a trailer connection was determined and then
a disconnection, either intentionally or unintentionally, has been sensed
during a given ignition cycle. It is also displayed if a trailer fault occurs
causing the trailer to appear disconnected. This message is also
displayed during manual activation without a trailer connected.
TBC FAULT:This message is displayed in response to faults sensed by
the TBC. In the event this message is seen, please take your vehicle to
an authorized dealer for diagnosis and repair. The TBC may still function,
but performance may be degraded.
WIRING FAULT ON TRAILER:The TBC is capable of determining
certain faults in the vehicle wiring and trailer wiring/brake system. These
faults do not mean there is anything wrong with the TBC. This message
is displayed when one of the following faults has occurred:
•Short circuit on the electric brake output wire:If the TRAILER
FAULT message is displayed with no trailer connected, the problem is
with the vehicle wiring from the TBC to the 7–pin connector in the
bumper. If the message is only displayed with a trailer connected, the
problem is related to the trailer wiring; consult your trailer dealer for
assistance. This can be a short to ground (i.e., chaffed wire) or a short
to voltage (i.e., pulled pin on trailer emergency break-away battery) or
trailer brakes drawing too much current.
Note:Your TBC can be diagnosed by your authorized dealer to
determine exactly which trailer fault has occurred; however, if the fault
is with the trailer this diagnosis isnotcovered under your Ford
warranty.
Points to Remember:
•Remember to adjust gain setting before using the TBC for the first
time.
•Readjust GAIN setting on the TBC (according to procedure above)
whenever road, weather and trailer or vehicle loading conditions
change from those that existed when the gain was initially set.
•The sliding lever on the TBC should be used only for manual
activation of trailer brakes to assist with proper adjustment of the
GAIN. Misuse, such as application during trailer sway, could cause
instability of trailer and/or tow vehicle.
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•Avoid towing in adverse weather conditions. The TBC does not
provide anti-lock control of the trailer wheels. Trailer wheels can
lock-up on slippery surfaces, resulting in reduced stability of trailer
and tow vehicle.
•The TBC interacts with the brake system of the vehicle, including
ABS, in order to reduce the likelihood of trailer wheel lockup.
Therefore, if these systems are not functioning properly the TBC may
not function at full performance.
•When the vehicle is turned off, the TBC Output is disabled and the
display is shut down. Reactivation of the ignition from 3 (OFF) to 4
(ON) will awaken the TBC module.
•The TBC is only a factory or dealer installed item. Ford is not
responsible for warranty or performance of the TBC due to misuse or
customer installation.
•Do not attempt removal of the TBC without consulting the
Workshop Manual.Damage to the unit may result.
Trailer lamps
Trailer lamps are required on most towed vehicles. Make sure all running
lights, brake lights, turn signals and hazard lights are working. See your
authorized dealer or trailer rental agency for proper instructions and
equipment for hooking up trailer lamps.
Using a step bumper (if equipped)
The rear bumper is equipped with an integral hitch and only requires a
ball with a one inch (25.4 mm) shank diameter. The bumper has a
5,000 lb. (2,270 kg) trailer weight and 500 lb. (227 kg) tongue weight
capacity.
If it is necessary to relocate the trailer hitch ball position, a
frame-mounted trailer hitch must be installed.
Driving while you tow
When towing a trailer:
•Do not drive faster than 70 mph (112 km/h) during the first 500 miles
(800 km) of trailer towing and don’t make full-throttle starts.
•Turn off the speed control. The speed control may shut off
automatically when you are towing on long, steep grades.
•Consult your local motor vehicle speed regulations for towing a trailer.
•To eliminate excessive transmission shifting, activate the Tow/Haul
feature. This will also assist in transmission cooling. (For additional
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information, refer to theUnderstanding the shift positions of the
5–speed automatic transmissionsection in theDrivingchapter.
•Anticipate stops and brake gradually.
•Do not exceed the GCWR rating or transmission damage may occur.
•Your vehicle may be equipped with a temporary or conventional spare
tire. If the spare tire is different in size (diameter and/or width), tread
type (All-Season or All-Terrain) or is from a different manufacturer
other than the road tires on your vehicle, your spare tire is considered
“temporary”. Consult information on the spare Tire Label or Safety
Compliance Certification Label for limitations when using.
Servicing after towing
If you tow a trailer for long distances, your vehicle will require more
frequent service intervals. Refer to yourscheduled maintenance
informationfor more information.
Trailer towing safety tips
General
•Ensure that the trailer, safety chains and 7–pin electrical connectors
are securely fastened.
•Make sure the truck receiver, draw bar, and coupler are properly
connected and adjusted.
•Check rear view and side mirrors for proper visibility especially when
towing trailer wider than the truck.
•When towing, operate the vehicle at lower speeds than you would
when not towing a trailer. The likelihood of trailer sway is greater at
higher speeds.
•If you will be towing a trailer frequently in hot weather, hilly
conditions, at GCWR, or any combination of these factors, consider
refilling your rear axle with synthetic gear lubricant if not already so
equipped. Refer toMaintenance Product Specifications and
Capacitiesin theMaintenance and Specificationschapter for the
proper axle lubricant. Remember that regardless of the rear axle
lubricant used, do not tow a trailer for the first 500 miles (800 km) of
a new vehicle, and that the first 500 miles of towing be done at no
faster than 70 mph (112 km/h) with no full-throttle starts.
•When turning make wide turns to allow trailer tires to properly clear
any obstacles.
•Be prepared for trailer sway due to buffeting when larger vehicles
pass in either direction.
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