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Using Anti-Lock
Do not pump the brakes. Just hold the brake pedal
down firmly and let anti-lock work for you. You may feel
the brakes pulsate, or you may hear air exhausting if
you have air brakes, but this is normal.
Braking in Emergencies
With anti-lock brakes, you can steer and brake at the
same time. In many emergencies, steering can help you
more than even the very best braking.
Trailer Brake Hand Control Valve
If your vehicle has this feature, the control is mounted
on the floor console.
This feature lets you apply
the trailer brakes without
applying the tractor brakes.You can apply the trailer brakes a little or apply them all
the way if you have to. Use this control only when
you are driving. Do not use it for parking or to hold the
rig on a hill.
{CAUTION:
Using the trailer brake hand control for parking
or for holding the vehicle on a hill may not
keep the vehicle from rolling. This can happen
if someone hits the valve by accident, or if air
pressure bleeds from the system. If the vehicle
rolls, you or others could be injured. To park
the vehicle or hold it on a hill, use the parking
brake properly.
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Trailer Connections
Heavy-Duty Trailer Wiring Package
Your vehicle may be equipped with an eight-wire trailer
towing harness. This harness, with a seven-pin
universal heavy-duty trailer connector, is attached to a
bracket on the platform hitch.
The Center High-Mounted Stoplamp (CHMSL) wire
is tied next to the trailer wiring harness for use with
a trailer.The eight-wire harness contains the following trailer
circuits:
•Yellow: Left Stop/Turn Signal
•Dark Green: Right Stop/Turn Signal
•Brown: Taillamps
•White: Ground
•Light Green: Back-up Lamps
•Light Blue: CHMSL
•Red: Battery Feed
•Dark Blue: Trailer Brake
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Trailer Connections
(C7/C8 Models Only)
If your vehicle has these trailer connections, they are
located at the rear of the cab for a tractor and at the rear
of the chassis when towing a trailer. There will be an
air connection and an electrical connection.
Be sure that the couplings to the trailer are
made correctly.
Air Connections
If you are not connecting the trailer air line connections
to another piece of equipment, be sure to replace
their protective caps.
Electrical Connections
This system is a seven-wire cable that will connect to
the trailer, supplying power to the trailer’s lighting
system. When not in use, it is stored in the trailer
air-hose storage bracket.
Power Take-Off (PTO)
If your vehicle is equipped
for the addition of a PTO,
this factory installed
switch will be located in
the instrument panel.
Before using a PTO, refer to the manufacturer’s or
installer’s instructions.
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Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This improves
fuel economy and reduces fan noise. Under heavy
vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise.
This is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
Power Steering Fluid
SeeScheduled Maintenance on page 6-5to determine
when to check your power steering fluid.
How To Check Power Steering Fluid
Check your power steering fluid only when the engine is
warm. If the engine is not warm, you probably will not
get an accurate reading.
If the fluid level is between the MIN (Minimum) and
MAX (Maximum) marks, you have enough. If you need
fluid, add only enough of the proper fluid to bring it
in between the MIN and MAX marks.
If your power steering fluid level is low, this can cause
the brake or service brakes soon warning lights to come
on. In addition, the steering effort and emergency
brake distance could increase.
If either light remains on after you have added power
steering fluid to the proper level, then shut off the engine
for 10 seconds. This should reset the brake warning
lights. If one or both lights stay on, see “Hydraulic Brake
System Warning Lights” underBrake System Warning
Light on page 3-31for more information.
What to Use
To determine what kind of fluid to use, seePart C:
Recommended Fluids and Lubricants on page 6-32.
Notice:When adding power steering uid or
making a complete uid change, always use the
proper uid. Failure to use the proper uid can
cause leaks and damage hoses and seals.
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