Step | Action | Yes | No | ||||
---|---|---|---|---|---|---|---|
DEFINITION: Testing the engagement and disengagement of the fan clutch. | |||||||
1 | Were you sent here from the diagnostic system check? | Go to Step 2 | |||||
2 | Is there excessive fan air noise? | Go to Step 3 | Go to Excessive Fan Noise | ||||
3 | Fan air noise is normal during cold engine start up. Does the fan noise go away at normal engine operating temperature? | Go to Step 13 | Go to Excessive Fan Noise | ||||
4 |
Important: The engine must be turned off and the engine temperature should be cold. Rotate the fan clutch. Does the fan clutch rotate? | Go to Step 5 | Go to Step 14 | ||||
5 | Visually inspect the fan blades for cracks, looseness or damage. Are the fan blades in good condition? | Go to Step 6 | Go to Step 15 | ||||
6 | Visually inspect the fan clutch for signs of silicone leakage.
Is the silicone fluid leakage excessive? | Go to Step 14 | Go to Step 7 | ||||
7 | Inspect the fan clutch for proper installation.
Is the fan blade loose at the fan clutch? | Go to Step 10 | Go to Step 8 | ||||
8 | Inspect the fan clutch for wear.
Important: Approximately 6.5 mm (¼ in) movement at the tip of the fan blade is normal. Is the fan clutch lateral movement excessive? | Go to Step 14 | Go to Step 9 | ||||
9 | The fan clutch should have more turning resistance when the engine is at or above normal operating temperature. Does the fan clutch have more resistance when the engine temperature is raised? | Go to Step 11 | Go to Step 14 | ||||
10 | Tighten the fan. Refer to Fan Clutch Replacement . Is the action complete? | Go to Step 16 | -- | ||||
11 | Perform a fan clutch engagement test.
Important: Do not allow engine temperature to exceed 121°C (250°F). Fan clutch engagement will be indicated by an increase in fan air noise, fan speed, and a drop of about 3-10°C (5-15°F) on the thermometer reading. Did the fan clutch engage between 85-96°C (185-205°F)? | Go to Step 12 | Go to Step 14 | ||||
12 | Once the fan clutch engages, perform the following steps:
Did the engine return to normal operating temperature? | Go to Step 13 | -- | ||||
13 | As the engine temperature returns to normal, the fan clutch will disengage, indicated by a reduction in fan air noise and fan speed. Did the fan clutch disengage? | Go to Step 16 | Go to Step 14 | ||||
14 | Replace the fan clutch. Refer to Fan Clutch Replacement . Is the repair complete? | Go to Step 16 | -- | ||||
15 | Replace the fan blades. Refer to Fan Clutch Replacement Is the repair complete? | Go to Step 16 | -- | ||||
16 | Operate the fan clutch to verify proper operation. Did you find and correct the condition? | System OK | Go to Step 2 |