F 350 4WD Pickup V8-7.3L DSL Turbo VIN F (1994)
Fan Clutch: Testing and Inspection
Fan Clutch Operational Test
WARNING: Do not operate the engine until the fan has been first checked for possible cracks and separations.
1. Run engine at a fast idle speed 1500 RPM until normal operating temperature is reached. This can be done more quickly by blocking off the front
of the radiator with cardboard.
NOTE: Regardless of temperatures, the unit must be operated for at least five minutes immediately before being tested.
2. Stop engine and, using a glove or a cloth to protect the hand, immediately check the effort required to turn the fan.
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If considerable effort is required, it can be assumed that the coupling is operating satisfactorily.
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If very little effort is required to turn the fan, the coupling is not operating properly and should be replaced.
Bi-Metallic Coiled Spring Removal
3. The clutch fan may be tested while the vehicle is being driven. To check, disconnect the bi-metallic spring, and rotate it 90° counterclockwise.
This disables the temperature-controlled, free-wheeling feature and the clutch performs like a conventional fan. If this cures the overheating
condition, replace the clutch fan.