brake JEEP WRANGLER 2008 User Guide

PARKING BRAKE
To set the parking brake, pull the lever up as firmly as
possible. When the parking brake is applied with the
ignition ON, the Brake Warning Light in the instrument
cluster will light. To release the parking brake, pull up
slightly, press the center button, then lower the lever
completely.
NOTE:The instrument cluster Brake Warning Light
indicates only that the parking brake is applied. You must
be sure the parking brake is fully applied before leaving
the vehicle.
Be sure the parking brake is firmly set when parked, and
the shift lever is in the PARK position (automatic trans-
mission), or REVERSE, or 1st gear (manual transmission).
When parking on a hill, you should apply the parking
brake before placing the shift lever in PARK, otherwise

WARNING!
Significant over or under-inflation of tires, or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness.
The Anti-Lock Brake System conducts a low speed self-
test at about 12 mph (20 km/h). If for any reason, your
foot is on the brake when the vehicle reaches 12 mph (20
km/h), this check will be delayed until 25 mph (40
km/h).
The Anti-Lock Brake System pump motor runs during
the self-test, and during an ABS stop, to provide the
regulated hydraulic pressure. The motor pump makes a
low humming noise during operation, this is normal. During off-road use, loss of traction can temporarily
defeat the system and cause the warning light to illumi-
nate. Turn the ignition OFF and ON again to restore
Anti-Lock Brake System function.

the front or rear axles has been exceeded, but the total
load is within the specified GVWR. If so, weight must be
shifted from front to rear, or rear to front, as appropriate
until the specified weight limitations are met. Store the
heavier items down low and be sure that the weight is
distributed equally. Stow all loose items securely before
driving.
Improper weight distributions can have an adverse affect
on the way your vehicle steers and handles, and the way
the brakes operate.

Trailer Tongue Weight (TW)
The trailer tongue weight is the downward force exerted
on the hitch ball by the trailer. In most cases it should not
be less than 10% or more than 15% of the trailer load. You
must consider this as part of the load on your vehicle.
Frontal Area
The frontal area is 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. It typically provides adjustable friction associ-
ated with the telescoping motion to dampen any un-
wanted 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 vehicle. This kind ofhitch is the most popular on the market today and is
commonly used to tow small and medium-sized trailers.
Weight-Distributing Hitch
A weight-distributing hitch system works by applying
leverage through spring (load) bars. It is typically used
for heavier loads, to distribute trailer tongue weight to
the tow vehicle’s front axle and the trailer axle(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.
346 STARTING AND OPERATING

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.
•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
PARK. With a manual transmission, shift the transmis-
sion into 1st gear. And with four-wheel-drive vehicles,
make sure the transfer case is not in N (Neutral).
Always, block orchockthe 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
354 STARTING AND OPERATING

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).

2. Park the booster vehicle within cable reach but with-
out letting the vehicles touch. Set the parking brake on
both vehicles, shift the automatic transmission into
PARK, or the manual transmission into NEUTRAL, and
turn the ignition OFF.
3. Turn off the heater, radio, and all unnecessary electri-
cal loads.
4. Connect one end of a jumper cable to the positive
terminal of the booster battery. Connect the other end of
the same cable to the positive terminal of the discharged
battery.

▫Driveline And Steering Component
Lubrication ..........................392
▫ Body Lubrication .....................392
▫ Windshield Wiper Blades ................392
▫ Windshield And Rear Window Washers .....393
▫ Exhaust System ......................393
▫ Cooling System .......................394
▫ Hoses And Vacuum/Vapor Harnesses .......399
▫ Brake System ........................399
▫ Automatic Transmission ................401
▫ Hydraulic Clutch Fluid — Manual
Transmission ........................403
▫ Manual Transmission ..................403
▫ Transfer Case ........................404 ▫
Front/Rear Axle Fluid ..................405
▫ Maintenance After Off-Road Driving ........405
▫ Appearance Care And Protection From
Corrosion ...........................406
 Fuses (Totally Integrated Power Module) ......413
 Vehicle Storage ........................419
 Replacement Bulbs — If Equipped ...........420
 Bulb Replacement ......................420
▫ Head Light ..........................420
▫ Front Park/Turn Signal .................421
▫ Front Side Marker .....................422
▫ Front Fog Light ......................422
▫ Rear Tail, Stop, Turn Signal, And Backup
Lights .............................422
376 MAINTAINING YOUR VEHICLE

Brake and Power Steering System Hoses
When servicing the vehicle for scheduled maintenance,
inspect surface of hoses for evidence of heat and me-
chanical damage. Hard and brittle rubber, cracking, tears,
cuts, abrasion, and excessive swelling suggest deteriora-
tion of the rubber. Particular attention should be made to
examining those hose surfaces nearest to high heat
sources, such as the exhaust manifold.
Inspect all hose clamps and couplings to make sure they
are secure and no leaks are present.
NOTE:Inspection of brake hoses should be done when-
ever the brake system is serviced and every engine oil
change.

To properly check the automatic transmission fluid level,
the following procedure must be used:
1. Operate the engine at idle speed and normal operating
temperature.
2. The vehicle must be on level ground.
3. Fully apply parking brake.
4. Place the gear selector momentarily in each gear
position ending with the lever in PARK.
5. Remove the dipstick, wipe it clean and reinsert it until
seated.
6. Remove the dipstick again and note the fluid level on
both sides. The fluid level should be between the HOT
(upper) reference holes on the dipstick at normal operat-
ing temperature. Verify that a solid coating of oil is seen
on both sides of the dipstick. If the fluid is low, add as
required into the dipstick tube.Do not overfill.Afteradding any quantity of oil through the dipstick tube, wait
a minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level.
NOTE:
If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two cold (lower) holes on the dipstick with
the fluid at approximately 70° F (21° C) (room tempera-
ture). If the fluid level is correctly established at room
temperature, it should be between the HOT (upper)
reference holes when the transmission reaches 180° F (21°
C). Remember it is best to check the level at the normal
operating temperature.
402 MAINTAINING YOUR VEHICLE