Ford MUSTANG Manual page 118

Continue to fill the reservoir until the coolant
is at the FULL COLD level.
Reinstall the pressure cap to the fully
installed position.
Start and idle the engine until the radiator
upper hose is warm (this indicates the
thermostat is open and coolant is flowing
through the entire system).
Immediately shut off the engine and let cool.
Cautiously remove the pressure relief cap and
add a 50/50 mixture of specified coolant and
water until the coolant is at the COLD FILL
level in the coolant reservoir.
Reinstall the pressure cap securely.
Check for leaks at the draincock.
Recheck the engine coolant level, using the
recommended procedure, after one or two
occasions of vehicle use.
Battery
Your vehicle may have a Motorcraft
maintenance-free battery. When the original
equipment battery is replaced under warranty, it
may be replaced by a Motorcraft
Low-Maintenance Battery.
The Low-Maintenance Battery has removable
vent caps for checking the electrolyte level and
for adding water, if necessary. The electrolyte
level should be checked at least every 24 months
or 24,000 miles (40,000 km) in temperatures up
to 90˚F (32˚C) and more often in temperatures
above 90˚F (32˚C). Keep the electrolyte level in
each cell up to the level indicator. Do not
overfill.
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