Another question on fan clutches

[Kenneth T.]

I have seen many posts on thermo clutch fans and the limited ways to test them. So, my question is............

If I use a hair dryer or heat gun (scared to do that), blown on the face of the clutch, to simulate an overheat condition. Will that cause a clutch response and lock up?

I am asking because I don't want to start and run the engine up to operating temp and then check the before and after effects. Thanks.

Ken

[Joe L.]

Re: Another question on fan clutches

I have seen many posts on thermo clutch fans and the limited ways to test them. So, my question is............

If I use a hair dryer or heat gun (scared to do that), blown on the face of the clutch, to simulate an overheat condition. Will that cause a clutch response and lock up?

I am asking because I don't want to start and run the engine up to operating temp and then check the before and after effects. Thanks.

Ken

Ken-----


The clutch will never "lock-up". It will simply become "stiffer" as the thermostat heats up. However, I don't think the testing methodology you describe will be effective at allowing you to determine the condition of the clutch.

[Kenneth T.]

Re: Another question on fan clutches

Thanks Joe,

My 454 gets warm in the stop and go. I remember when that occured I would hear a noise, a whoosh, that let me know that the fan was in.
I wanted to follow up on the usual suspects.

Thanks,

Ken

[Joe L.]

Re: Another question on fan clutches

Thanks Joe,

My 454 gets warm in the stop and go. I remember when that occured I would hear a noise, a whoosh, that let me know that the fan was in.
I wanted to follow up on the usual suspects.

Thanks,

Ken

Ken-----


The noise you heard is the increased fan noise caused by the "stiffening up" of the viscous coupling of the fan clutch. However, the fan clutch never "locks-up". Engagement and disengagement is a gradual process but engagement never goes anywhere near the point of "lock-up".

[Duke W.]

Re: Another question on fan clutches

I think a big (1500 Watt) hair dryer or shop heat gun will heat up the thermostat enough to cause the clutch to stiffen. Give it a try. I don't think it will do any damage.

When cold the fan will turn only about 1500 RPM, and maximum clutch stiffness allows about 3500.

Duke