2023 JEEP WRANGLER coolant reservoir

306
SERVICING AND MAINTENANCE
SCHEDULED SERVICING — GASOLINE
ENGINE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Operating conditions such as
frequent short-trips, trailer tow, extremely hot or cold
ambient temperatures will influence when the “Change
Oil” or “Oil Change Required” message is displayed. Have
your vehicle serviced as soon as possible, within the next
500 miles (805 km).On vehicles equipped with instrument cluster display, “Oil
Change Required” will be displayed and a single chime will
sound, indicating that an oil change is necessary.
On non-instrument cluster display equipped vehicles,
“Change Oil” will flash in the instrument cluster odometer
and a single chime will sound, indicating that an oil
change is necessary.
An authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other than
an authorized dealer, the message can be reset by
referring to the steps described under Instrument Cluster
Display for further information
Úpage 108.
NOTE:Under no circumstances should oil change intervals
exceed 10,000 miles (16,000 km), 12 months or 350
hours of engine run time, whichever comes first. The 350
hours of engine run or idle time is generally only a concern
for fleet customers.
Once A Month Or Before A Long Trip:

Check the engine oil level.
 Check the windshield washer fluid level.
 Check the tire inflation pressures and look for unusual
wear or damage, rotate at the first sign of irregular
wear.
 Check the fluid levels of the coolant reservoir, brake
master cylinder, and power steering, and fill as needed.
 Check the function of all interior and exterior lights.

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310SERVICING AND MAINTENANCE
SCHEDULED SERVICING — DIESEL ENGINE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Operating conditions such as
frequent short-trips, trailer tow, extremely hot or cold
ambient temperatures will influence when the “Oil Change
Required” message is displayed. Have your vehicle
serviced as soon as possible, within the next 500 miles
(805 km).
An authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other than
an authorized dealer, to reset the message
Úpage 108.
NOTE:Under no circumstances should oil change intervals
exceed 10,000 miles (16,000 km) or 12 months,
whichever comes first.
Engine Oil Filter Replacement
Residual oil in the housing may spill from the housing
when the new filter is installed if the residual oil is not
either removed from the housing or enough time has not
elapsed to allow the oil to drain back into the engine.
When servicing the oil filter on this engine, open the filter
cap approximately six turns until the cap o-ring is visible
and stop. Wait five minutes with the cap in this position to
allow dirty engine oil to drain back into the engine. After
five minutes, the cap and filter assembly can be removed
and discarded. When installing the new oil filter cartridge
assembly, ensure the cap is tightened to the specified
torque to prevent low oil pressure conditions. Once A Month Or Before A Long Trip:

Check engine oil level
 Check windshield washer fluid level
 Check the tire pressures and look for unusual wear or
damage
 Check the fluid levels of the coolant reservoir, brake
master cylinder, and fill as needed
 Check function of all interior and exterior lights

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314SERVICING AND MAINTENANCE
ENGINE COMPARTMENT
2.0L GASOLINE ENGINE
1 — Battery 6 — Brake Fluid Reservoir Cap
2 — Power Distribution Center (Fuses) 7 — Washer Fluid Reservoir Cap
3 — Engine Oil Dipstick 8 — Engine Air Cleaner Filter
4 — Engine Oil Fill 9 — Power Steering Reservoir Cap
5 — Engine Coolant Pressure Cap 10 — Intercooler Coolant Reservoir Cap

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SERVICING AND MAINTENANCE315
3.6L GASOLINE ENGINE
1 — Power Distribution Center (Fuses) 7 — Power Pack Unit Pressure Cap — If Equipped
2 — Battery 8 — Washer Fluid Reservoir Cap
3 — Engine Oil Dipstick 9 — Engine Air Cleaner Filter
4 — Engine Oil Fill 10 — Power Steering Reservoir Cap
5 — Engine Coolant Pressure Cap 11 — Motor Generator Unit Coolant Pressure Cap— If Equipped
6 — Brake Fluid Reservoir Cap
8

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316SERVICING AND MAINTENANCE
3.0L DIESEL ENGINE
1 — Battery 6 — Power Distribution Center (Fuses)
2 — Engine Oil Fill 7 — Power Steering Reservoir Cap
3 — Engine Coolant Pressure Reservoir Cap 8 — Engine Oil Dipstick
4 — Brake Fluid Reservoir Cap 9 — Engine Air Cleaner Filter
5 — Washer Fluid Reservoir Cap

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SERVICING AND MAINTENANCE331
(Continued)
With the engine OFF and cold, the level of the engine
coolant should be within the OK range between the ADD
and FULL range on the dipstick.

1. Remove the cap with level dipstick from the engine
coolant bottle.

2. Clean off the coolant from the dipstick.
3. Rest the cap on the opening of the coolant bottle without tightening the cap.
4. Remove the cap with dipstick and check the coolant level on the dipstick.
The radiator normally remains completely full, so there is
no need to remove the radiator/coolant pressure cap
unless checking for engine coolant 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 is needed to maintain the
proper level, only OAT coolant that meets the
requirements of the manufacturer Material Standard
MS.90032 should be added to the coolant bottle. Do not
overfill.
Cooling System Notes
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 (antifreeze) 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 needs
to be added, the contents of the coolant expansion
bottle must also be protected against freezing.
 If frequent engine coolant additions are required, the
cooling system should be pressure tested for leaks.
 Maintain engine coolant concentration at a minimum
of 50% OAT coolant (conforming to MS.90032) and
distilled water for proper corrosion protection of your
engine which contains aluminum components.
 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 cooling performance,
poor gas mileage, and increased emissions.BRAKE SYSTEM
In order to ensure brake system performance, all brake
system components should be inspected periodically. For
the proper maintenance intervals
Úpage 307.
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
Úpage 376.
WARNING!
Riding the brakes can lead to brake failure and possibly
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.
WARNING!
Use only the manufacturer recommended brake fluid Úpage 376. 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.
8

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