Jeep Wrangler JK (2018 year). Instruction

Selection Of Coolant

Refer to “Fluids And Lubricants” in “Technical Specifica-
tions” for further information.

CAUTION!

• Mixing of engine coolant (antifreeze) other than speci-

fied Organic Additive Technology (OAT) engine coolant
(antifreeze), may result in engine damage and may
decrease corrosion protection. Organic Additive Tech-
nology (OAT) engine coolant is different and should not
be mixed with Hybrid Organic Additive Technology
(HOAT) engine coolant (antifreeze) or any “globally
compatible” coolant (antifreeze). If a non-OAT engine
coolant (antifreeze) is introduced into the cooling sys-
tem in an emergency, the cooling system will need to be
drained, flushed, and refilled with fresh OAT coolant
(conforming to MS.90032), by an authorized dealer as
soon as possible.

• Do not use water alone or alcohol-based engine

coolant (antifreeze) products. Do not use additional
rust inhibitors or antirust products, as they may not
be compatible with the radiator engine coolant and
may plug the radiator.

(Continued)

CAUTION! (Continued)

• This vehicle has not been designed for use with

propylene glycol-based engine coolant (antifreeze).
Use of propylene glycol-based engine coolant (anti-
freeze) is not recommended.

Adding Coolant

Your vehicle has been built with an improved engine
coolant (OAT coolant conforming to MS.90032) that allows
extended maintenance intervals. This engine coolant (anti-
freeze) can be used up to ten years or 150,000 miles
(240,000 km) before replacement. To prevent reducing this
extended maintenance period, it is important that you use
the same engine coolant (OAT coolant conforming to
MS.90032) throughout the life of your vehicle.

Please review these recommendations for using Organic
Additive Technology (OAT) engine coolant (antifreeze)
that meets the requirements of FCA Material Standard
MS.90032. When adding engine coolant (antifreeze):
• We recommend using Mopar Antifreeze/Coolant 10

Year/150,000 Mile (240,000 km) Formula OAT (Organic
Additive Technology) that meets the requirements of
FCA Material Standard MS.90032.

SERVICING AND MAINTENANCE

387

• Mix a minimum solution of 50% OAT engine coolant

that meets the requirements of FCA Material Standard
MS.90032 and distilled water. Use higher concentrations
(not to exceed 70%) if temperatures below −34°F (−37°C)
are anticipated. Please contact an authorized dealer for
assistance.

• Use only high purity water such as distilled or deionized

water when mixing the water/engine coolant (anti-
freeze) solution. The use of lower quality water will
reduce the amount of corrosion protection in the engine
cooling system.

NOTE:
• It is the owner’s responsibility to maintain the proper

level of protection against freezing according to the
temperatures occurring in the area where the vehicle is
operated.

• Some vehicles require special tools to add coolant prop-

erly. Failure to fill these systems properly could lead to
severe internal engine damage. If any coolant is needed
to be added to the system, please contact a local autho-
rized dealer.

• Mixing engine coolant (antifreeze) types is not recom-

mended and can result in cooling system damage. If

HOAT and OAT coolant are mixed in an emergency, have
a authorized dealer drain, flush, and refill with OAT
coolant (conforming to MS.90032) as soon as possible.

Cooling System Pressure Cap

The cap must be fully tightened to prevent loss of engine
coolant (antifreeze), and to ensure that engine coolant
(antifreeze) will return to the radiator from the coolant
expansion bottle/recovery tank if so equipped.

The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.

WARNING!

• Do not open hot engine cooling system. Never add

engine coolant (antifreeze) when the engine is over-
heated. Do not loosen or remove the cap to cool an
overheated 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.

• Do not use a pressure cap other than the one speci-

fied for your vehicle. Personal injury or engine
damage may result.

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SERVICING AND MAINTENANCE

Disposal Of Used Coolant

Used ethylene glycol-based coolant (antifreeze) is a regu-
lated substance requiring proper disposal. Check with your
local authorities to determine the disposal rules for your
community. To prevent ingestion by animals or children,
do not store ethylene glycol-based coolant in open contain-
ers or allow it to remain in puddles on the ground. If
ingested by a child or pet, seek emergency assistance
immediately. Clean up any ground spills immediately.

Coolant Level

The coolant bottle provides a quick visual method for
determining that the coolant level is adequate. With the
engine OFF and cold, the level of the engine coolant
(antifreeze) in the bottle should be between the ranges
indicated on the bottle.

The radiator normally remains completely full, so there is
no need to remove the radiator/coolant pressure cap
unless checking for engine coolant (antifreeze) freeze point
or replacing coolant. Advise your 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 engine coolant (antifreeze) is needed to
maintain the proper level, only OAT coolant that meets the
requirements of FCA Material Standard MS.90032 should
be added to the coolant bottle. Do not overfill.

Points To Remember

NOTE:

When the vehicle is stopped after a few miles/

kilometers 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
accumulating on the radiator and being vaporized when
the thermostat opens, allowing hot engine coolant (anti-
freeze) 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.
• Do not overfill the coolant expansion bottle.
• Check the coolant freeze point in the radiator and in the

coolant expansion bottle. If engine coolant (antifreeze)
needs to be added, the contents of the coolant expansion
bottle must also be protected against freezing.

• If frequent engine coolant (antifreeze) additions are

required, the cooling system should be pressure tested
for leaks.

SERVICING AND MAINTENANCE

389

• Maintain engine coolant (antifreeze) concentration at a

minimum of 50% OAT coolant (conforming to
MS.90032) and distilled water for proper corrosion pro-
tection of your engine which contains aluminum com-
ponents.

• Make sure that the coolant expansion bottle overflow

hoses are not kinked or obstructed.

• Keep the front of the radiator clean. If your vehicle is

equipped with air conditioning, keep the front of the
condenser clean.

• Do 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 engine coolant (antifreeze) performance,
poor gas mileage, and increased emissions.

Brake System

In order to assure brake system performance, all brake
system components should be inspected periodically. Refer
to the “Maintenance Plan” in this section for the proper
maintenance intervals.

WARNING!

Riding the brakes can lead to brake failure and possi-
bly a collision. 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 would not have your full braking
capacity in an emergency.

Fluid Level Check — Brake Master Cylinder

The fluid level of the master cylinder should be checked
whenever the vehicle is serviced, or immediately if the
brake system warning light is on. If necessary, add fluid to
bring level within the designated marks on the side of the
reservoir of the brake master cylinder. Be sure to clean the
top of the master cylinder area before removing cap. 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. If the brake fluid is abnormally low, check the
system for leaks.

Refer to “Fluids And Lubricants” in “Technical Specifica-
tions” for further information.

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SERVICING AND MAINTENANCE

WARNING!

• Use only manufacturer’s recommended brake fluid.

Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information. Using the
wrong type of brake fluid can severely damage your
brake system and/or impair its performance. The
proper type of brake fluid for your vehicle is also
identified on the original factory installed hydraulic
master cylinder reservoir.

• To avoid contamination from foreign matter or mois-

ture, use only new brake fluid or fluid that has been
in a tightly closed container. Keep the master cylin-
der reservoir cap secured at all times. Brake fluid in
a open container absorbs moisture from the air
resulting in a lower boiling point. This may cause it
to boil unexpectedly during hard or prolonged brak-
ing, resulting in sudden brake failure. This could
result in a collision.

• Overfilling the brake fluid reservoir can result in

spilling brake fluid on hot engine parts, causing the
brake fluid to catch fire. Brake fluid can also damage
painted and vinyl surfaces, care should be taken to
avoid its contact with these surfaces.

(Continued)

WARNING! (Continued)

• Do not allow petroleum based fluid to contaminate

the brake fluid. Brake seal components could be
damaged, causing partial or complete brake failure.
This could result in a collision.

Front/Rear Axle Fluid

For normal service, periodic fluid level checks are not
required. When the vehicle is serviced for other reasons the
exterior surfaces of the axle assembly should be inspected.
If gear oil leakage is suspected inspect the fluid level. Refer
to “Fluids And Lubricants” in “Technical Specifications”
for further information.

Fluid Level Check

Lubricant should be at the 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 the manufacturer’s recommended fluid. Refer to
“Fluids And Lubricants” in “Technical Specifications” for
further information.

SERVICING AND MAINTENANCE

391

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

Add fluid at the filler hole, until it runs out of the hole,
when the vehicle is in a level position.

Drain

First remove the fill plug (B), then the drain plug (C). The
recommended tightening torque for the drain and fill plugs
is 15 to 25 ft lbs (20 to 34 N·m).

CAUTION!

When replacing the plugs, do not overtighten them.
You could damage them and cause them to leak.

Selection Of Lubricant

Use only the manufacturer’s recommended fluid. Refer to
“Fluids And Lubricants” in “Technical Specifications” for
further information.

Automatic Transmission

Selection Of Lubricant

It is important to use the proper transmission fluid to
ensure optimum transmission performance and life. Use
only the manufacturer’s specified transmission fluid. Refer
to “Fluids And Lubricants” in “Technical Specifications”
for fluid specifications. It is important to maintain the
transmission fluid at the correct level using the recom-
mended fluid.

Transfer Case

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SERVICING AND MAINTENANCE

NOTE:

No chemical flushes should be used in any trans-

mission; only the approved lubricant should be used.

CAUTION!

Using a transmission fluid other than the manufactur-
er’s recommended fluid may cause deterioration in
transmission shift quality and/or torque converter
shudder, and will require more frequent fluid and
filter changes. Refer to “Fluids And Lubricants” in
“Technical Specifications” for fluid specifications.

Special Additives

The manufacturer strongly recommends against using any
special additives in the transmission. Automatic Transmis-
sion Fluid (ATF) is an engineered product and its perfor-
mance may be impaired by supplemental additives. There-
fore, do not add any fluid additives to the transmission.
The only exception to this policy is the use of special dyes
for diagnosing fluid leaks. Avoid using transmission seal-
ers as they may adversely affect seals.

CAUTION!

Do not use chemical flushes in your transmission as
the chemicals can damage your transmission compo-
nents. Such damage is not covered by the New Vehicle
Limited Warranty.

Fluid Level Check

It is best to check the fluid level when the transmission is
at normal operating temperature (approximately 180°F/
82°C). This occurs after at least 15 miles (25 km) of driving.
At normal operating temperature, the fluid cannot be held
comfortably between the fingertips.

Use the following procedure to check the transmission
fluid level properly:

1. Park the vehicle on level ground.

2. Remove the engine cover by pulling it up off the

mounting studs (two in the front and two in the rear).

3. Run the engine at normal idle speed for at least 60

seconds, and leave the engine running for the rest of this
procedure.

4. Fully apply the parking brake, and press the brake

pedal.

SERVICING AND MAINTENANCE

393

5. Place the gear selector momentarily into each gear

position (allowing time for the transmission to fully
engage in each position), ending with the transmission
in PARK.

6. Remove the dipstick, wipe it clean and reinsert it until

seated.

7. Remove the dipstick again and note the fluid level on

both sides. The fluid level reading is only valid if there
is a solid coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full of fluid if
the actual level is at or above the hole. The fluid level
should be between the HOT (upper) reference holes on
the dipstick at normal operating temperature. If the
fluid level is low, add fluid through the dipstick tube to
bring it to the proper level. Do not overfill. Use ONLY
the specified fluid (refer to

⬙Fluids And Lubricants⬙

under “Technical Specifications” for fluid specifica-
tions). After adding 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:

• The holes in the dipstick will be full of fluid if the

actual level is at or above the hole.

• If it is necessary to check the transmission below the

operating temperature, the fluid level should be be-
tween the two COLD (lower) holes on the dipstick
with the fluid at approximately 80°F (27°C). If the fluid
level is correctly established at 80° F (27°C), it should
be between the HOT (upper) reference holes when the
transmission reaches 180° F (82°C). Remember it is best
to check the level at the normal operating temperature.

CAUTION!

If the fluid temperature is below 50°F (10°C) it may not
register on the dipstick. Do not add fluid until the
temperature is elevated enough to produce an accurate
reading. Run the engine at idle, in PARK, to warm the
fluid.

8. Reinstall the engine cover and snap it down securely

onto the four mounting studs.

9. Check for leaks. Release the parking brake.

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SERVICING AND MAINTENANCE

NOTE:

To prevent dirt and water from entering the

transmission after checking or replenishing fluid, make
sure that the dipstick cap is properly reseated. It is normal
for the dipstick cap to spring back slightly from its fully
seated position, as long as its seal remains engaged in the
dipstick tube.

Fluid And Filter Changes

Refer to the “Maintenance Plan” for the proper mainte-
nance intervals.

In addition, change the fluid and filter if the fluid becomes
contaminated (with water, etc.), or if the transmission is
disassembled for any reason.

Manual Transmission

Selection Of Lubricant

Use only manufacturer’s recommended manual transmis-
sion fluid. Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information.

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 3/16 of an inch (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. If the fluid becomes contaminated with water,
it should be changed immediately. Otherwise, change the
fluid as recommended in the Maintenance Plan. Refer to
the “Maintenance Plan” for the proper maintenance inter-
vals.

RAISING THE VEHICLE

In the case where it is necessary to raise the vehicle, go to
an authorized dealer or service station.

TIRES

Tire Safety Information

Tire safety information will cover aspects of the following
information: Tire Markings, Tire Identification Numbers,
Tire Terminology and Definitions, Tire Pressures, and Tire
Loading.

SERVICING AND MAINTENANCE

395

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.
Example: P215/65R15 95H.

• European — Metric tire sizing is based on European

design standards. Tires designed to this standard have
the tire size molded into the sidewall beginning with the
section width. The letter

⬙P⬙ is absent from this tire size

designation. Example: 215/65R15 96H.

• LT (Light Truck) — Metric tire sizing is based on U.S.

design standards. The size designation for LT-Metric
tires is the same as for P-Metric tires except for the letters
“LT” that are molded into the sidewall preceding the
size designation. Example: LT235/85R16.

• Temporary spare tires are designed for temporary emer-

gency use only. Temporary high pressure compact spare
tires have the letter “T” or “S” molded into the sidewall
preceding the size designation. Example: T145/80D18
103M.

• High flotation tire sizing is based on U.S. design stan-

dards and it begins with the tire diameter molded into
the sidewall. Example: 31x10.5 R15 LT.

Tire Markings

1 — U.S. DOT Safety
Standards Code (TIN)

4 — Maximum Load

2 — Size Designation

5 — Maximum Pressure

3 — Service Description

6 — Treadwear, Traction
and Temperature Grades

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SERVICING AND MAINTENANCE

Tire Sizing Chart

EXAMPLE:

Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT
P

= Passenger car tire size based on U.S. design standards, or

ⴖ....blank....ⴖ = Passenger car tire based on European design standards, or
LT

= Light truck tire based on U.S. design standards, or

T or S

= Temporary spare tire or

= Overall diameter in inches (in)

215, 235, 145

= Section width in millimeters (mm)

65, 85, 80

= Aspect ratio in percent (%)

– Ratio of section height to section width of tire, or
10.5

= Section width in inches (in)

= Construction code

–

⬙R⬙ means radial construction, or

–

⬙D⬙ means diagonal or bias construction

15, 16, 18

= Rim diameter in inches (in)

Service Description:
95

= Load Index

– A numerical code associated with the maximum load a tire can carry

SERVICING AND MAINTENANCE

397

EXAMPLE:

= Speed Symbol

– A symbol indicating the range of speeds at which a tire can carry a load corresponding to its load index under cer-

tain operating conditions

– The maximum speed corresponding to the speed symbol should only be achieved under specified operating condi-

tions (i.e., tire pressure, vehicle loading, road conditions, and posted speed limits)

Load Identification:
Absence of the following load identification symbols on the sidewall of the tire indicates a Standard Load (SL) tire:

• XL = Extra load (or reinforced) tire, or

• LL = Light load tire or

• C, D, E, F, G = Load range associated with the maximum load a tire can carry at a specified pressure
Maximum Load

– Maximum load indicates the maximum load this tire is designed to carry

Maximum Pressure

– Maximum pressure indicates the maximum permissible cold tire inflation pressure for this tire

Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire; however,
the date code may only be on one side. Tires with white
sidewalls will have the full TIN, including the date code,
located on the white sidewall side of the tire. Look for the TIN

on the outboard side of black sidewall tires as mounted on the
vehicle. If the TIN is not found on the outboard side, then you
will find it on the inboard side of the tire.

EXAMPLE:

DOT MA L9 ABCD 0301

DOT

= Department of Transportation

– This symbol certifies that the tire is in compliance with the U.S. Department of Transportation tire safety standards

and is approved for highway use

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SERVICING AND MAINTENANCE

EXAMPLE:

= Code representing the tire manufacturing location (two digits)

= Code representing the tire size (two digits)

ABCD

= Code used by the tire manufacturer (one to four digits)

= Number representing the week in which the tire was manufactured (two digits)

– 03 means the 3rd week
01

= Number representing the year in which the tire was manufactured (two digits)

– 01 means the year 2001
– Prior to July 2000, tire manufacturers were only required to have one number to represent the year in which the

tire was manufactured. Example: 031 could represent the 3rd week of 1981 or 1991

Tire Terminology And Definitions

Term

Definition

B-Pillar

The vehicle B-Pillar is the structural member of the body located be-
hind the front door.

Cold Tire Inflation Pressure

Cold tire inflation pressure is defined as the tire pressure after the
vehicle has not been driven for at least three hours, or driven less
than 1 mile (1.6 km) after sitting for a minimum of three hours. In-
flation pressure is measured in units of PSI (pounds per square inch)
or kPa (kilopascals).

SERVICING AND MAINTENANCE

399

Term

Definition

Maximum Inflation Pressure

The maximum inflation pressure is the maximum permissible cold
tire inflation pressure for this tire. The maximum inflation pressure is
molded into the sidewall.

Recommended Cold Tire Inflation Pressure

Vehicle manufacturer’s recommended cold tire inflation pressure as
shown on the tire placard.

Tire Placard

A label permanently attached to the vehicle describing the vehicle’s
loading capacity, the original equipment tire sizes and the recom-
mended cold tire inflation pressures.

Tire Loading And Tire Pressure

NOTE:

The proper cold tire inflation pressure is listed on

the driver’s side B-Pillar or the rear edge of the driver’s
side door.

Check the inflation pressure of each tire, including the
spare tire (if equipped), at least monthly and inflate to the
recommended pressure for your vehicle.

Example Tire Placard Location (Door)

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SERVICING AND MAINTENANCE

This placard tells you important information about the:

1. Number of people that can be carried in the vehicle.

2. Total weight your vehicle can carry.

3. Tire size designed for your vehicle.

4. Cold tire inflation pressures for the front, rear, and spare

tires.

Loading

The vehicle maximum load on the tire must not exceed the
load carrying capacity of the tire on your vehicle. You will
not exceed the tire’s load carrying capacity if you adhere to
the loading conditions, tire size, and cold tire inflation
pressures specified on the Tire and Loading Information
placard in “Vehicle Loading” in the “Starting And Operat-
ing” section of this manual.

NOTE:

Under a maximum loaded vehicle condition, gross

axle weight ratings (GAWRs) for the front and rear axles
must not be exceeded.

For further information on GAWRs, vehicle loading, and
trailer towing, refer to “Vehicle Loading” in the “Starting
And Operating” section of this manual.

To determine the maximum loading conditions of your
vehicle, locate the statement “The combined weight of
occupants and cargo should never exceed XXX kg or
XXX lbs” on the Tire and Loading Information placard. The
combined weight of occupants, cargo/luggage and trailer
tongue weight (if applicable) should never exceed the
weight referenced here.

Steps For Determining Correct Load Limit—

(1) Locate the statement “The combined weight of
occupants and cargo should never exceed XXX kg or
XXX lbs.” on your vehicle’s placard.

(2) Determine the combined weight of the driver and
passengers that will be riding in your vehicle.

(3) Subtract the combined weight of the driver and
passengers from XXX kg or XXX lbs.

(4) The resulting figure equals the available amount of
cargo and luggage load capacity. For example, if “XXX”
amount equals 1400 lbs. and there will be five 150 lb
passengers in your vehicle, the amount of available
cargo and luggage load capacity is 650 lbs. (1400-750
(5x150) = 650 lbs.)

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SERVICING AND MAINTENANCE

Jeep Wrangler JK (2018 year). Instruction - part 25