Jeep Gladiator 2021 Owner's Manual page 412

410 SERVICING AND MAINTENANCE
WARNING!
Do not open hot engine cooling system.

Never add engine coolant (antifreeze) when
the engine is overheated. 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 specified for your vehicle. Personal
injury or engine damage may result.
Disposal Of Used Coolant
Used ethylene glycol-based coolant (antifreeze)
OAT or HOAT, is a regulated 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 containers or allow
it to remain in puddles on the ground, clean up
any ground spills immediately. If ingested, seek
emergency assistance immediately.
Coolant Level
The coolant bottle provides a quick visual
method for determining that the coolant level is
adequate. With the engine in the 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 freeze point or replacing
coolant. Advise your service attendant of this.
As long as the engine operating temperature is
satisfactory, the coolant only needs to be
checked once a month.
When additional engine coolant 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.
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 compart-
ment. This is normally a result of moisture from
rain, snow, or high humidity accumulating on
the radiator and being vaporized when the ther-
mostat 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 freezing point of the coolant in the

radiator and in the coolant expansion bottle.
If determined that more engine coolant
needs to be added to the radiator, 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 pres-
sure 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.