What are the symptoms of a bad fan clutch? - Chevelle Tech
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post #1 of 6 (permalink) Old May 18th, 02, 1:07 PM Thread Starter
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How can you tell if a fan clutch is bad? I found one with a 772 fan that appears to have leaked a little fluid but still has resistance if you turn it. Also are these cluches supposed to lockup completely when hot?
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post #2 of 6 (permalink) Old May 18th, 02, 7:17 PM
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I would stay away from a leaky clutch, one of the symptoms is that the engine sounds like an airplane. The fans usually lock up at about 160 degrees.

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post #3 of 6 (permalink) Old May 18th, 02, 11:20 PM
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No, they do not lock up entirely when hot. A hand turn while hot or cold won't tell you much really. If it has leaked oil consider it shot. Even a little oil loss makes them work poorly since they don't have much oil in the first place.

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post #4 of 6 (permalink) Old May 19th, 02, 1:01 AM
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I have heard the test is when you shut the engine off. If the engine is hot, the fan should stop soon after you turn it off, not spin freely.

sound right?
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post #5 of 6 (permalink) Old May 19th, 02, 11:28 PM
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They can fail in many ways.

1. Any fluid leakage means it's toast.

2. They can seize solid. That's the "sounds like an airplane" way.

3. They can fail to engage. Engine overheats.

4. With the clutch firmly bolted to the waterpump, any fore/aft play in the fan blades means the bearings are shot. This often happens before the bearings lock up, as in #2 above. If the thing craps out the bearings badly enough, the fan goes through the radiator. Ouch.
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post #6 of 6 (permalink) Old May 20th, 02, 8:39 AM Thread Starter
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Thanks guys, I think I will get a new one and be safe.

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