brake RAM CHASSIS CAB 2007 Service Manual

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
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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

Improper weight distributions can have an adverse effect
on the way your vehicle steers and handles and the way
the brakes operate.
CAUTION!Do not load your vehicle any heavier than the
GVWR or the maximum front and rear GAWR. If
you do, parts on your vehicle can break, or it can
change the way your vehicle handles. This could
cause you to lose control. Also overloading can
shorten the life of your vehicle. An EXAMPLE of a loaded vehicle is shown in the
following chart. Note that neither GVWR nor GAWR
capabilities are exceeded. Overloading can cause poten-
tial safety hazards and shorten service life.
NOTE: The weights shown in this chart are not
necessarily the weights for your vehicle. Also, the
amount of load added to both the front and rear axles
can be computed after the vehicle has been weighed
both in its  curb weight  condition, and in its  loaded
and ready for operation  condition.340 STARTING AND OPERATING

Frontal Area
The maximum height and maximum width of the front of
a trailer.
Trailer Sway Control
The trailer sway control is a telescoping link that can be
installed between the hitch receiver and the trailer tongue
that typically provides adjustable friction associated with
the telescoping motion to dampen any unwanted trailer
swaying motions while traveling.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch ball or
some other connecting point of the truck. These kind of
hitches are the most popular on the market today and
they’re commonly used to tow small- and medium-sized
trailers. Weight-Distributing Hitch
A weight-distributing system works by applying lever-
age through spring (load) bars. They are typically used
for heavier loads, to distribute trailer tongue weight to
the tow vehicle’s front axle and the trailer axel(s). When
used in accordance with the manufacturers’ directions, it
provides for a more level ride, offering more consistent
steering and brake control thereby enhancing towing
safety. The addition of a friction / hydraulic sway control
also dampens sway caused by traffic and crosswinds and
contributes positively to tow vehicle and trailer stability.
Trailer sway control and a weight distributing (load
equalizing) hitch are recommended for heavier Tongue
Weights (TW) and may be required depending on Vehicle
and Trailer configuration / loading to comply with gross
axle weight rating (GAWR) requirements. STARTING AND OPERATING 343
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WARNING!An improperly adjusted Weight Distributing Hitch
system may reduce handling, stability, braking per-
formance, and could result in an accident.
Weight Distributing Systems may not be compatible
with Surge Brake Couplers. Consult with your hitch
and trailer manufacturer or a reputable Recreational
Vehicle dealer for additional information.
Weight Distributing Hitch System344 STARTING AND OPERATING

CAUTION!• Avoid towing a trailer for the first 500 miles (805
km) of vehicle operation. Doing so may damage
your vehicle.
• During the first 500 miles (805 km) of trailer
towing, limit your speed to 50 mph (80 km/h).
WARNING!Your vehicle may require special axle lubricant.
Please refer to the fluids section of this manual.
Perform the maintenance listed in Section 8 of this
manual. When towing a trailer, never exceed the GAWR,
or GCWR, ratings. WARNING!Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have an accident.
• When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis structure or tires.348 STARTING AND OPERATING

• Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
frame or hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.
• Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle automatic transmission in
P for Park. With a manual transmission, shift the
transmission into reverse. And with four-wheel-drive
vehicles, make sure the transfer case is not in neutral.
Always, block or  chock  the trailer wheels.
• GCWR must not be exceeded.
• Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR 2. GTW
3. GAWR
4. Tongue weight rating for the trailer hitch utilized
(This requirement may limit the ability to always
achieve the 10% to 15% range of tongue weight as a
percentage of total trailer weight).
Towing Requirements — Tires
Do not attempt to tow a trailer while using a compact
spare tire.
Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to the
Tires–General Information section of this manual on
Tire Pressures for proper tire inflation procedures.
Also, check the trailer tires for proper tire inflation
pressures before trailer usage. STARTING AND OPERATING 349
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Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to the Tires–General
Information section of this manual on Tread Wear
Indicators for the proper inspection procedure.
When replacing tires refer to the Tires–General Infor-
mation section of this manual on Replacement Tires for
proper tire replacement procedures. Replacing tires
with a higher load carrying capacity will not increase
the vehicle’s GVWR and GAWR limits.
Towing Requirements — Trailer Brakes
Do not interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
An electronically actuated trailer brake controller is
required when towing a trailer with electronically actuated brakes. When towing a trailer equipped with
a hydraulic surge actuated brake system, an electronic
brake controller is not required.
Trailer brakes are recommended for trailers over 1,000
lbs (454 kg) and required for trailers in excess of 2,000
lbs (907 kg).
CAUTION!If the trailer weighs more than 1,000 lbs (454 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do this
could lead to accelerated brake lining wear, higher
brake pedal effort, and longer stopping distances.350 STARTING AND OPERATING

WARNING!Do not connect trailer brakes to your vehicle’s hy-
draulic brake lines. It can overload your brake sys-
tem and cause it to fail. You might not have brakes
when you need them and could have an accident.
Towing any trailer will increase your stopping dis-
tance. When towing you should allow for additional
space between your vehicle and the vehicle in front
of you. Failure to do so could result in an accident. Towing Requirements — Trailer Lights & Wiring
Whenever you pull a trailer, regardless of the trailer size,
stop lights and turn signals on the trailer are required for
motoring safety.
The Trailer Tow Package may includ ea4and7pin
wiring harness. Use a factory approved trailer harness
and connector.
NOTE: Do not cut or splice wiring into the vehicles
wiring harness. STARTING AND OPERATING 351
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NOTE: During snowplow usage on vehicles equipped
with an overhead console module, the outside tempera-
ture display will show higher temperatures than the
outside ambient temperature. The higher displayed tem-
perature is due to blocked or reduced airflow to the
underhood ambient temperature sensor by the snow-
plow. This is common and outside temperature display
operation will return to normal when the snowplow is
removed.
General Maintenance
Snowplows should be maintained in accordance with the
plow manufacturer’s instructions.
Keep all snowplow electrical connections and battery
terminals clean and free of corrosion. When plowing snow, to avoid transmission and driv-
etrain damage, the following precautions should be ob-
served.
• Operate with transfer case in 4L when plowing small
or congested areas where speeds are not likely to
exceed 15 mph (24 km/h). At higher speeds operate in
4H.
• Vehicles with automatic transmissions should use 4L
range when plowing deep or heavy snow for extended
periods of time to avoid transmission overheating.
• Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal before shifting
the transmission. STARTING AND OPERATING 359
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