Jeep 2004 Wrangler - Manual (Page 241)

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 -37°F (-38°C) 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
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