wheel RAM CHASSIS CAB 2007 Service Manual

WARNING!• Always fully apply the parking brake when leav-
ing your vehicle, or it may roll and cause damage
or injury. Also be certain to leave an automatic
transmission in Park, a manual transmission in
Reverse or First gear. Failure to do so may allow
the vehicle to roll and cause damage or injury.
• Never leave children alone in a vehicle. Leaving
children in a vehicle unattended is dangerous for
a number of reasons. A child or others could be
seriously or fatally injured. Don’t leave the keys
in the ignition. A child could operate power
windows, other controls, or move the vehicle.
• Be sure the parking brake is fully disengaged
before driving, failure to do so can lead to brake
problems due to excessive heating of the rear
brakes. When parking on a hill, turn the front wheels toward the
curb on a downhill grade and away from the curb on an
uphill grade.
The parking brake should always be applied whenever
the driver is not in the vehicle.
BRAKE SYSTEM
If power assist is lost for any reason (for example,
repeated brake applications with the engine off), the
brakes will still function. However, you will experience a
substantial increase in braking effort to stop the vehicle.
If either the front or rear hydraulic systems lose normal
capability, the remaining system will still function with
some loss of overall braking effectiveness. This will be
evident by increased pedal travel during application,
greater pedal force required to slow or stop, and activa-
tion of the BRAKE warning lamp and the ABS lamp (if
equipped) during brake use. STARTING AND OPERATING 301
5

Brake Noise
During normal operation of the brake system certain
noises may be present from time to time. Occasional
 groan  or  squeal  noises may occur during normal
operation of the brake system which may not be indica-
tive of a problem. These noises may be heard at any time
the brakes are applied but may be more noticeable during
the first few brake applications in the morning. Moisture,
hot or cold temperature, dust, and or other debris may
also contribute to the noise condition. Repeated or con-
tinuous noises during braking may be an indication that
the brake linings are worn and in need of replacement. Four-Wheel Anti-Lock Brake System
WARNING!Anti-Lock Brake Systems contain sophisticated elec-
tronic equipment. It may be susceptible to interfer-
ence caused by improperly installed or high output
radio transmitting equipment. This interference can
cause possible loss of anti-lock braking capability.
Installation of such equipment should be performed
by qualified professionals.302 STARTING AND OPERATING

WARNING!• Anti-lock system (ABS) cannot prevent the natu-
ral laws of physics from acting on the vehicle, nor
can it increase braking or steering efficiency be-
yond that afforded by the condition of the vehicle
brakes and tires or the traction afforded.
• The ABS cannot prevent accidents, including
those resulting from excessive speed in turns,
following another vehicle too closely, or hydro-
planing. Only a safe, attentive, and skillful driver
can prevent accidents.
• The capabilities of an ABS equipped vehicle must
never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety
or the safety of others. This Anti-lock Brake System is designed to aid the driver
in maintaining vehicle control under adverse braking
conditions. The system operates with a separate com-
puter to modulate hydraulic pressure to prevent wheel
lockup and help avoid skidding on slippery surfaces.
The system’s pump motor runs during an ABS stop to
provide regulated hydraulic pressure. The pump motor
makes a low humming noise during operation. This is
normal.
When you are in a severe braking condition involving
use of the Anti-lock Brake System, you will experience
some pedal drop as the vehicle comes to a complete stop.
This is the result of the system reverting to the base brake
system and is normal.
Engagement of the Anti-lock Brake System may be
accompanied by a pulsing sensation. You may also hear a
clicking noise. These occurrences are normal, and indi-
cate that the system is functioning. STARTING AND OPERATING 303
5

ABS Warning Light
The Anti-lock Brake System includes an amber warning
light, located in the instrument cluster. When the light is
illuminated, the Anti-lock Brake System is not function-
ing. The system reverts to standard non-anti-lock brakes.
WARNING!Pumping of the anti-lock brakes will diminish their
effectiveness and may lead to an accident. Pumping
makes the stopping distance longer. Just press firmly
on your brake pedal when you need to slow down or
stop. POWER STEERING
The standard power steering system will give you good
vehicle response and increased ease of maneuverability
in tight spaces. The system will provide mechanical
steering capability if power assist is lost.
If for some reason, the power assist is interrupted, it will
still be possible to steer your vehicle. Under these condi-
tions you will observe a substantial increase in steering
effort, especially at very low vehicle speeds and during
parking maneuvers.
NOTE: Increased noise levels at the end of the steering
wheel travel are considered normal and does not indicate
that there is a problem with the power steering system.
Upon initial start-up in cold weather, the power steering
pump may make noise for a short period of time. This is
due to the cold, thick fluid in the steering system. This
noise should be considered normal, and does not in any
way damage the steering system.304 STARTING AND OPERATING

WARNING!Continued operation with reduced power steering
assist could pose a safety risk to yourself and others.
Service should be obtained as soon as possible.
CAUTION!Prolonged operation of the steering system at the
end of the steering wheel travel will increase the
steering fluid temperature and should be avoided
when possible. Damage to the power steering pump
may occur. TIRE SAFETY INFORMATION
Tire Markings
NOTE:
• P (Passenger)-Metric tire sizing is based on U.S. design
standards. P-Metric tires have the letter “P” molded
into the sidewall preceding the size designation. Ex-
ample: P215/65R15 95H. STARTING AND OPERATING 305
5

Tire Pressures for High Speed Operation
The manufacturer advocates driving at safe speeds
within posted speed limits. Where speed limits or condi-
tions are such that the vehicle can be driven at high
speeds, maintaining correct tire inflation pressure is very
important. Increased tire pressure and reduced vehicle
loading may be required for high-speed vehicle opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!High speed driving with your vehicle under maxi-
mum load is dangerous. The added strain on your
tires could cause them to fail. You could have a
serious accident. Don’t drive a vehicle loaded to the
maximum capacity at continuous speeds above 75
mph (120 km/h). Radial-Ply Tires
WARNING!Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial ply tires in sets of four (or 6, in case
of trucks with dual rear wheels). Never combine
them with other types of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized tire dealer for radial tire repairs. STARTING AND OPERATING 317
5

Compact Spare Tire — If Equipped
The compact spare is for temporary emergency use with
radial tires. It is engineered to be used on your style
vehicle only. Since this tire has limited tread life, the
original tire should be repaired (or replaced) and rein-
stalled at the first opportunity.
WARNING!Temporary use spare tires are for emergency use
only. With these tires, do not drive more than 50 mph
(80 km/h). Temporary-use spare tires have limited
tread life. When the tread is worn to the tread wear
indicators, the temporary use spare tire needs to be
replaced. Be sure to follow the warnings, which
apply to your spare. Failure to do so could result in
spare tire failure and loss of vehicle control. Do not install a wheel cover or attempt to mount a
conventional tire on the compact spare wheel, since the
wheel is designed specifically for the compact spare.
Do not install more than one compact spare tire/wheel
on the vehicle at any given time.
CAUTION!Because of the reduced ground clearance, do not take
your vehicle through an automatic car wash with the
compact spare installed. Damage to the vehicle may
result.318 STARTING AND OPERATING

Limited Use Spare — If Equipped
The limited use spare tire is for temporary emergency use
on your vehicle. This tire is identified by a limited use
spare tire warning label located on the limited use spare
tire and wheel assembly. This tire may look like the
original equipped tire on the front or rear axle of your
vehicle, but it is not. Installation of this limited use spare
tire affects vehicle handling. Since it is not the same tire,
replace (or repair) the original tire and reinstall on the
vehicle at the first opportunity. WARNING!The limited use spare tires are for emergency use
only. Installation of this limited use spare tire affects
vehicle handling. With this tire, do not drive more
than 60 mph (100 km/h). Keep inflated to the cold
tire inflation pressure listed on either your tire
placard or limited use spare tire and wheel assembly.
Replace (or repair) the original tire at the first
opportunity and reinstall it on your vehicle. Failure
to do so could result in loss of vehicle control.
Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels above 30 mph (48 km/h).
Refer to the paragraph on “Freeing A Stuck Vehicle” in
Section 6 of this manual. STARTING AND OPERATING 319
5

WARNING!Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure
someone. Do not spin your vehicle’s wheels faster
than 30 mph (48 km/h) for more than 30 seconds
continuously when you are stuck, and don’t let
anyone near a spinning wheel, no matter what the
speed.
Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced. These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes 1/16 inch (2 mm). When the tread is worn to the
tread wear indicators, the tire should be replaced.
Many states have laws requiring tire replacement at this
point.320 STARTING AND OPERATING

WARNING!• Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combina-
tions of unapproved tires and wheels may
change suspension dimensions and performance
characteristics, resulting in changes to steering,
handling, and braking of your vehicle. This can
cause unpredictable handling and stress to steer-
ing and suspension components. You could lose
control and have an accident resulting in serious
injury or death. Use only the tire and wheel sizes
with load ratings approved for your vehicle.
• Never use a tire with a smaller load index or
capacity, other than what was originally
equipped on your vehicle. Using a tire with a
smaller load index could result in tire overload-
ing and failure. You could lose control and have
an accident.
• Failure to equip your vehicle with tires having
adequate speed capability can result in sudden
tire failure and loss of vehicle control. CAUTION!Replacing original tires with tires of a different size
may result in false speedometer and odometer read-
ings.
Alignment And Balance
Poor suspension alignment may result in:
• Fast tire wear.
• Uneven tire wear, such as feathering and one-sided
wear.
• Vehicle pull to right or left.
Tires may also cause the vehicle to pull to the left or right.
Alignment will not correct this condition. See your dealer
for proper diagnosis.322 STARTING AND OPERATING