•It may be necessary to increase the coolant concentration
above 50%.
•NEVER increase the coolant concentration above 60%.
•Engine coolant concentrations above 60% will decrease the
overheat protection characteristics of the engine coolant and
may cause engine damage.
•If available, refer to the chart on the coolant container to
ensure the coolant concentration in your vehicle will provide
adequate freeze protection at the temperatures in which you
drive in the winter months.
If you drive in extremely hot climates:
•It is still necessary to maintain the coolant concentration
above 40%.
•NEVER decrease the coolant concentration below 40%.
•Engine coolant concentrations below 40% will decrease the
corrosion protection characteristics of the engine coolant and
may cause engine damage.
•Engine coolant concentrations below 40% will decrease the
freeze protection characteristics of the engine coolant and may
cause engine damage.
•If available, refer to the chart on the coolant container to
ensure the coolant concentration in your vehicle will provide
adequate protection at the temperatures in which you drive.
Vehicles driven year-round in non-extreme climates should use a 50/50
mixture of engine coolant and distilled water for optimum cooling system
and engine protection.
Fan clutches
Your vehicle’s cooling system is equipped with a viscous fan clutch.
•The fan clutch helps control cooling, increase performance, improve
fuel economy and reduce noise.
•The fan clutch is controlled by bimetallic spring sensors. Do not
tamper with these sensors as this may change their calibration or keep
the fan clutch from operating at all.
Stay clear of the fan/fan area while the engine is running or
possible personal injury may occur.
2006 F-650/750(f67)
Supplement
USA(fus)
Maintenance and Specifications
184
