How fail-safe cooling works
If the engine begins to overheat:
•The engine coolant temperature
gauge will move to the red (hot)
area.
•The message center will indicate
the engine is overheating.
•The
indicator will
illuminate.
If the engine reaches a preset over-temperature condition, the engine
will automatically switch to alternating cylinder operation. Each disabled
cylinder acts as an air pump and cools the engine.
When this occurs the vehicle will still operate. However:
•The engine power will be limited.
•The air conditioning system will be disabled.
Continued operation will increase the engine temperature and the engine
will completely shut down, causing steering and braking effort to
increase.
Once the engine temperature cools, the engine can be re-started. Take
your vehicle to a service facility as soon as possible to minimize engine
damage.
When fail-safe mode is activated
You have limited engine power when in the fail-safe mode, so drive the
vehicle with caution. The vehicle will not be able to maintain high-speed
operation and the engine will run rough. Remember that the engine is
capable of completely shutting down automatically to prevent engine
damage, therefore:
1. Pull off the road as soon as safely possible and turn off the engine.
2. Arrange for the vehicle to be taken to a service facility.
3. If this is not possible, wait a short period for the engine to cool.
4. Check the coolant level and replenish if low.
Never remove the coolant reservoir cap while the engine is
running or hot.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
361
ProCarManuals.com
The transmission fluid should be in
this range if at normal operating
temperature (150°F-170°F
[66°C-77°C]).
The transmission fluid should be in
this range if at ambient temperature
(50°F-95°F [10°C-35°C]).
High fluid level
Fluid levels above the safe range
may result in transmission failure.
An overfill condition of transmission
fluid may cause shift and/or
engagement concerns and/or possible damage.
High fluid levels can be caused by an overheating condition.
Adjusting automatic transmission fluid levels
Before adding any fluid, make sure the correct type is used. The type of
fluid used is normally indicated on the dipstick handle and also in the
Maintenance Product Specifications and Capacitiessection in this
chapter.
Use of a non-approved automatic transmission fluid may cause
internal transmission component damage.
If necessary, add fluid in 1/2 pint (250 ml) increments through the filler
tube until the level is correct.
If an overfill occurs, excess fluid
should be removed by a qualified
technician.
An overfill condition of
transmission fluid may cause shift and/or engagement concerns
and/or possible damage.
Do not use supplemental transmission fluid additives, treatments or
cleaning agents. The use of these materials may affect transmission
operation and result in damage to internal transmission components.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
377
ProCarManuals.com