FORD 2004 F-550 v.2 - Manual (Page 260)

However, the fluid level should be checked if the transmission is not
working properly, i.e., if the transmission slips or shifts slowly or if you
notice some sign of fluid leakage.
Automatic transmission fluid expands when warmed. To obtain an
accurate fluid check, drive the vehicle until it is at normal operating
temperature (approximately 30 km [20 miles]). If your vehicle has been
operated for an extended period at high speeds, in city traffic during hot
weather or pulling a trailer, the vehicle should be turned off for about 30
minutes to allow fluid to cool before checking.
1. Drive the vehicle 30 km (20 miles) or until it reaches normal operating
temperature.
2. Park the vehicle on a level surface and engage the parking brake.
3. With the parking brake engaged and your foot on the brake pedal,
start the engine and move the gearshift lever through all of the gear
ranges. Allow sufficient time for each gear to engage.
4. Latch the gearshift lever in P (Park) and leave the engine running.
5. Remove the dipstick, wiping it clean with a clean, dry lint free rag. If
necessary, refer to Identifying components in the engine compartment
in this chapter for the location of the dipstick.
6. Install the dipstick making sure it is fully seated in the filler tube.
7. Remove the dipstick and inspect the fluid level. The fluid should be in
the designated area for normal operating temperature or ambient
temperature.
Low fluid level
Do not drive the vehicle if the fluid
level is at the bottom of the dipstick
and the ambient temperature is
above 10°C (50°F).
Correct fluid level
The transmission fluid should be
checked at normal operating
temperature 66°C-77°C
(150°F-170°F) on a level surface. The normal operating temperature can
be reached after approximately 30 km (20 miles) of driving.
You can check the fluid without driving if the ambient temperature is
above 10°C (50°F). However, if fluid is added at this time, an overfill
condition could result when the vehicle reaches normal operating
temperature.
ADD COLD HOT DO NOT ADD
DON'T ADD IF IN CROSSHATCHED AREA • CHECK WHEN HOT IDLING IN PARK
2004 F250/350/450/550 (f23)
Owners Guide (post-2002-fmt)
USA English (fus)
Maintenance and Specifications
260