2004 JEEP WRANGLER engine

Windshield Washers
The fluid reservoir in the engine compartment should be
checked for fluid level at regular intervals. Fill the
reservoir with windshield antifreeze (not radiator anti-
freeze) rated not to freeze at -25ÉF (-31ÉC). Operate the
system for a few seconds to flush out the residual water.
WARNING!
Commercial windshield washer solvents are flam-
mable. They could ignite and burn you. Care must
be exercised when filling or working around the
washer solution.
Windshield Washer Aiming
To change the aim of the windshield washers, place a
safety pin into the nozzle opening and move the nozzle
slightly. Continue making slight adjustments until you
obtain the desired pattern.
Exhaust System
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained engine exhaust
system.
238 MAINTAINING YOUR VEHICLE

If you notice a change in the sound of the exhaust system;
or if the exhaust fumes can be detected inside the vehicle;
or when the underside or rear of the vehicle is damaged;
have an authorized technician inspect the complete ex-
haust system and adjacent body areas for broken, dam-
aged, deteriorated, or mispositioned parts. Open seams
or loose connections could permit exhaust fumes to seep
into the passenger compartment. In addition, inspect the
exhaust system each time the vehicle is raised for lubri-
cation or oil change. Replace as required.
Cooling System
WARNING!
You or others can be badly burned by hot coolant or
steam from your radiator. If you see or hear steam
coming from under the hood, don't open the hood
until the radiator has had time to cool. Never try to
open a cooling system pressure cap when the radia-
tor or coolant bottle is hot.
Coolant Checks
Check coolant protection every 12 months (before the
onset of freezing weather, where applicable). If coolant is
dirty or rusty in appearance, the system should be
drained, flushed and refilled with fresh coolant.
Check the front of the radiator for any accumulation of
bugs, leaves, etc. Clean the radiator by gently spraying
water from a garden hose at the back of the core.
Check the engine cooling system hoses for condition and
tightness of connection. Inspect the entire system for
leaks. Any hoses that show cuts or severe abrasion must
be replaced.
Cooling System Ð Drain, Flush, And Refill
At the intervals shown in the appropriate ªMaintenance
Schedule,º the system should be drained, flushed, and
refilled.
If the solution is dirty and contains a considerable
amount of sediment, clean and flush with reliable cooling
system cleaner. Follow with a thorough rinsing to remove
all deposits and chemicals.
MAINTAINING YOUR VEHICLE 239
7

Engine Coolant Disposal
Used ethylene glycol based engine coolant is a regulated
substance requiring proper disposal. Check with your
local authorities to determine the disposal rules for your
community. Do not store ethylene glycol based engine
coolant in open containers or allow it to remain in
puddles on the ground. Prevent ingestion by animals or
children. If ingested by a child, contact a physician
immediately.
Selection Of Coolant
Use only the manufacturer's recommended coolant, refer
to Recommended Fluids, Lubricants, and Genuine Parts
for correct coolant type.
CAUTION!
²Mixing of coolants other than the specified HOAT
coolant may result in decreased corrosion protec-
tion and engine damage that may not be covered
under the new vehicle warranty. If a non-HOAT
coolant is introduced into the cooling system in an
emergency, it should be replaced with the speci-
fied coolant as soon as possible.
²Do not use plain water alone or alcohol base
antifreeze products. Do not use additional rust
inhibitors or antirust products, as they may not be
compatible with the radiator coolant and may
plug the radiator.
²This vehicle has not been designed for use with
Propylene Glycol based coolants. Use of Propy-
lene Glycol base coolants is not recommended.
240 MAINTAINING YOUR VEHICLE

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
MAINTAINING YOUR VEHICLE 241
7

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.
242 MAINTAINING YOUR VEHICLE

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.
MAINTAINING YOUR VEHICLE 243
7

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.
244 MAINTAINING YOUR VEHICLE

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.
MAINTAINING YOUR VEHICLE 245
7