Checking Fluid Level
On Aerostar, Bronco II and Ranger, fluid level may be checked when fluid is either hot or cold. If fluid is approximately 75°F (24°C), check fluid level using COLD full mark on dipstick. If fluid is approximately 177°F (77°C), check fluid level using HOT full mark on dipstick.
On Bronco and "E" and "F" series, run engine until fluid reaches normal operating temperature, 165-175°F (74-79°C). Turn steering wheel all the way from left to right several times. Turn off engine. Check fluid level in reservoir. Add fluid as required.