Dodge 2004 Caravan Owner's Manual page 320

320 MAINTAINING YOUR VEHICLE
Adding Coolant
When adding coolant, or refilling the system, a minimum
of 50% solution of ethylene glycol antifreeze coolant in
water should be used. Higher concentrations (not to
exceed 70%) are required if temperatures below
( 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.
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.
NOTE: Mixing coolant types will decrease the life of the
engine coolant and will require more frequent coolant
changes.
Coolant Pressure Cap
The coolant pressure cap must be fully tightened to
prevent loss of coolant, and to insure that coolant will
return to the radiator from the coolant recovery bottle.
37°F The coolant pressure cap should be inspected and
cleaned if there is any accumulation of foreign material
on the sealing surfaces.
The warning words "DO NOT OPEN HOT" on the
coolant pressure cap are a safety precaution. Never
add coolant to the radiator when the engine is over-
heated. Do not loosen or remove the coolant pressure
cap to cool an overheated engine. Heat causes pres-
sure to build up in the cooling system. To prevent
scalding or injury, do not remove the coolant pressure
cap while the system is hot or under pressure.
WARNING!