2004 JEEP WRANGLER Owners Manual

Adding Coolant
When adding coolant, a minimum solution of recom-
mended 50% ethylene glycol antifreeze coolant in water
should be used. Use higher concentrations (not to exceed
70%) if temperatures below -37ÉF (-38ÉC) are anticipated.
Use only high purity water such as distilled or deionized
water when mixing the water/antifreeze solution. The
use of lower quality water will reduce the amount of
corrosion protection in the engine cooling system.
NOTE:Mixing coolant types will decrease the life of the
engine coolant and will require more frequent engine
coolant changes.
Please note that it is the owner's responsibility to main-
tain the proper level of protection against freezing ac-
cording to the temperatures occurring in the area where
the vehicle is operated.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of
coolant, and to insure that coolant will return to the
radiator from the coolant reserve tank.The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
WARNING!
The warning words DO NOT OPEN HOT on the
cooling system pressure cap are a safety precaution.
Never add coolant when the engine is overheated.
Do not loosen or remove the cap to cool an over-
heated engine. Heat causes pressure to build up in
the cooling system. To prevent scalding or injury, do
not remove the pressure cap while the system is hot
or under pressure.
Coolant Level
The coolant bottle provides a quick visual method for
determining that the coolant level is adequate. The
coolant level must be at the FULL mark or above the
ADD mark on the bottle.
The radiator normally remains completely full, so there is
not need to remove the radiator cap unless checking for
coolant freeze point or replacing coolant. Advise your
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service attendant of this. As long as the engine operating
temperature is satisfactory, the coolant bottle need only
be checked once a month.
When additional coolant is needed to maintain the
proper level, it should be added to the coolant bottle. Do
not overfill.
Points To Remember
NOTE:
When the vehicle is stopped after a few miles of
operation, you may observe vapor coming from the front
of the engine compartment. This is normally a result of
moisture from rain, snow, or high humidity accumulat-
ing on the radiator and being vaporized when the
thermostat opens, allowing hot coolant to enter the
radiator.
If an examination of your engine compartment shows no
evidence of radiator or hose leaks, the vehicle may be
safely driven. The vapor will soon dissipate.
²Do not overfill the coolant bottle.
²Check coolant freeze point in the system.
²If frequent coolant additions are required, or if the
level in the recovery bottle does not drop when the
engine cools, the cooling system should be pressure
tested for leaks.
²Maintain coolant concentration at 50% ethylene glycol
antifreeze (minimum) in water for proper corrosion
protection of your engine that contains aluminum
components.
²Make sure that the radiator and coolant bottle hoses
are not kinked or obstructed.
²Do not change the thermostat for summer or winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory cooling performance, poor gas
mileage, and increased emissions.
Hoses and Vacuum/Vapor Harnesses
Inspect surfaces of hoses and nylon tubing for evidence
of heat and mechanical damage. Hard or soft spots,
brittle rubber, cracking, tears, cuts, abrasions, and exces-
sive swelling indicate deterioration of the rubber.
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Pay particular attention to the hoses nearest to high heat
sources such as the exhaust manifold. Inspect hose rout-
ing to be sure hoses do not touch any heat source or
moving component that may cause heat damage or
mechanical wear.
Insure nylon tubing in these areas has not melted or
collapsed. Inspect all hose connections such as clamps
and couplings to make sure they are secure and no leaks
are present. Components should be replaced immedi-
ately if there is any evidence of degradation that could
cause failure.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Refer to the appropriate ªMaintenance Scheduleº in
Section 8 for suggested service intervals.
WARNING!
Riding the brakes can lead to brake failure and
possibly an accident. Driving with your foot resting
or riding on the brake pedal can result in abnormally
high brake temperatures, excessive lining wear, and
possible brake damage. You wouldn't have your full
braking capacity in an emergency.
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
whenever the brake system is serviced and every engine
oil change.
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WARNING!
Worn brake hoses can burst and cause brake failure.
You could have an accident. If you see any signs of
cracking, scuffing, or worn spots, have the brake
hoses replaced immediately.
Brake Master Cylinder
The fluid level in the master cylinder should be checked
when performing under hood services, or immediately if
the BRAKE warning light shows system failureBe sure to clean the top of the master cylinder area before
removing the cap. If necessary, add fluid to bring the
fluid level up to the requirements described on the brake
fluid reservoir. With disc brakes, fluid level can be
expected to fall as the brake pads wear. Brake fluid level
should be checked when pads are replaced. However,
low fluid level may be caused by a leak and a checkup
may be needed.
Use only manufacturer's recommended brake fluid, refer
to Recommended Fluids, Lubricants, and Genuine Parts
for correct fluid type.
WARNING!
²Use of a brake fluid that may have a lower initial
boiling point or unidentified as to specification,
may result in sudden brake failure during hard
prolonged braking. You could have an accident.
²Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts and the
brake fluid catching fire.
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Use only brake fluid that has been in a tightly closed
container to avoid contamination from foreign matter. Do
not allow petroleum base fluid to contaminate the brake
fluid as seal damage will result.
Automatic Transmission
Selection of Lubricant
It is important that the proper lubricant is used in the
transmission to assure optimum transmission perfor-
mance. Use only manufacturer's recommended transmis-
sion fluid, refer to Recommended Fluids, Lubricants, and
Genuine Parts for correct fluid type. It is important that
the transmission fluid be maintained at the prescribed
level using the recommended fluid.
CAUTION!
Using a transmission fluid other than the manufac-
turer's recommended fluid may cause deterioration
in transmission shift quality and/or torque converter
shudder. Using a transmission fluid other than the
manufacturer's recommended fluid will result in
more frequent fluid and filter changes. Refer to
Recommended Fluids, Lubricants, and Genuine
Parts for correct fluid type.
Fluid Level Check Ð 42RLE
This fluid level should be checked when the engine is
fully warmed up and the fluid in the transmission is
heated to its normal operating temperature. Operation of
the transmission with an improper fluid level will greatly
reduce the life of the transmission and of the fluid.
To check the automatic transmission fluid level properly,
the following procedure must be used:
1. The vehicle must be on level ground.
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2. The engine should be running at curb idle speed for a
minimum of 60 seconds.
3. Fully apply parking brake.
4. Apply the brakes and shift the transmission into P
(Park).
5. The fluidMUSTbe checked with the transmission in
P (Park) to be sure that the fluid level is accurate.
6. Wipe the dipstick clean and reinsert until seated.
Remove dipstick and note reading.
At normal operating temperature (approximately 180É F
(82É C), the fluid level is correct if it is in the HOT region
(cross-hatched area) on the oil level indicator. The fluid
level indicator should be in the COLD region at 70É F (21É
C) fluid temperature.
If the fluid level is low, add sufficient fluid to bring to the
proper level. Refer to Recommended Fluids, Lubricants
and Genuine Parts for correct fluid type.
Fluid is added through the dipstick tube.NOTE:To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
certain that the dipstick cap is properly reseated.
Special Additives
The manufacturer strongly recommends against the ad-
dition of any additives to the transmission. The only
exception to this policy is the use of special dyes to aid in
detecting fluid leaks. The use of transmission sealers
should be avoided as they may adversely affect seals.
Hydraulic Clutch Fluid Ð Manual Transmission
The clutch hydraulic system is a sealed maintenance free
system. In the event of leakage or other malfunction, the
system must be replaced.
Manual Transmission
Selection of Lubricant
Use only manufacturer's recommended manual trans-
mission fluid, refer to Recommended Fluids, Lubricants,
and Genuine Parts for correct fluid type.
246 MAINTAINING YOUR VEHICLE

Fluid Level Check
Check the fluid level by removing the fill plug. The fluid
level should be between the bottom of the fill hole and a
point not more than 3/16º (4.76 mm) below the bottom of
the hole.
Add fluid, if necessary, to maintain the proper level.
Frequency of Fluid Change
Under normal operating conditions, the fluid installed at
the factory will give satisfactory lubrication for the life of
the vehicle. Fluid changes are not necessary unless the
lubricant has become contaminated with water. If con-
taminated with water, the fluid should be changed im-
mediately.
Transfer Case
Fluid Level Check
The fluid level should be to the bottom edge of the fill
hole (A) when the vehicle is in a level position.
Adding Fluid
Fluid should be added only at filler hole until fluid
begins to run out of the hole.
Drain
First remove fill plug (B), then drain plug (C). Recom-
mended tightening torque for drain and fill plugs is
15±25 ft.lbs. (20±34 N´m).
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CAUTION!
When replacing plugs, do not overtighten. You could
damage them and cause them to leak.
Selection of Lubricant
Use only manufacturer's recommended fluid, refer to
Recommended Fluids, Lubricants, and Genuine Parts for
correct fluid type.
Front/Rear Axle FluidFluid Level Check
Lubricant should be at bottom edge of the oil fill hole.
Adding Fluid
Add lubricant only at the fill hole and only to the level
specified above.
Selection of Lubricant
Use only manufacturer's recommended fluid, refer to
Recommended Fluids, Lubricants, and Genuine Parts for
correct fluid type.
Appearance Care And Protection From Corrosion
Protection Of Body And Paint From Corrosion
Vehicle body care requirements vary according to geo-
graphic locations and usage. Chemicals that make roads
passable in snow and ice, and those that are sprayed on
trees and road surfaces during other seasons, are highly
corrosive to the metal in your vehicle. Outside parking,
which exposes your vehicle to airborne contaminants,
road surfaces on which the vehicle is operated, extreme
hot or cold weather and other extreme conditions will
have an adverse effect on paint, metal trim, and under-
body protection.
248 MAINTAINING YOUR VEHICLE