Ford Windstar Owner's Manual page 296

Leave the coolant in all year. Make sure that the coolant will
not freeze at the temperature level in which you usually drive
during winter months. Keep an engine coolant in your engine
that has a protection rating of at least
To find out how much engine coolant mixture your vehicle's
coolant system can hold, see Refill Capacities in Capacities and
Specifications chapter.
You may add water by itself only in an emergency, but you
should replace it with a 50/50 mixture of water and coolant as
soon as possible.
Have your dealer check the engine cooling system for leaks if
you have to add engine coolant more than once a month, or
you have to add more than a quart (liter) at a time.
Checking Hoses
Inspect all engine and heater system hoses for deterioration,
leaks and loose clamps before adding or replacing engine
coolant. Make whatever repairs or replacements are necessary
using Motorcraft parts or their equivalents.
Engine Coolant Drain and Flush
To drain and flush your engine coolant, you MUST see your
Ford dealer or refer to the procedure in the service manual.
Failing to do so could result in engine damage.
Power Steering Fluid
Check the level of the power steering fluid at least twice a
year (i.e., every Spring and Fall).
To check the level of your power steering fluid:
Start the engine and let it run until the power steering fluid
1.
reaches normal operating temperature. The power steering
fluid will reach the right temperature after at least five
minutes of idling or at least one mile (1 km) of driving.
296
20˚F ( 29˚C).