Clutch fan

[JAsaro]

Ok this one has me puzzled just started driving the fan is off when I get to my location and if my temperature makes the fan come on and it won’t shut off and the air pressure in the secondary tank starts to drop the fan will not shut off until that air tank pressure hundred psi also come on if I make the air pressure drops below 90/95 psi I am thinking it could be the clutch fan solenoid on the firewall? Thank you

[Coronado126]

On big trucks, air is used to release the fan clutch and turn it off.

If your air pressure goes below 100 psi your fan clutch is supposed to "fail on" and lock so the engine can't overheat.

I'm losing some of the context of the problem from your post, but from I understand what you're saying, you don't have a fan problem per se, you have an air pressure problem somewhere else on the truck and you're noticing the fan staying on because it's the loudest part.

Now, if your fan kicks on like normal when your engine starts warming up, and then after it's cooled down your fan doesn't unlock and you start losing air pressure when your engine coolant temp has returned to a normal range, then yes, I'd suspect your fan solenoid is sticking and leaking air.

[Mattman]

So do you have an air leak?

[JAsaro]

(11-11-2020 )Coronado126 Wrote:  On big trucks, air is used to release the fan clutch and turn it off.

If your air pressure goes below 100 psi your fan clutch is supposed to "fail on" and lock so the engine can't overheat.

I'm losing some of the context of the problem from your post, but from I understand what you're saying, you don't have a fan problem per se, you have an air pressure problem somewhere else on the truck and you're noticing the fan staying on because it's the loudest part.

Now, if your fan kicks on like normal when your engine starts warming up, and then after it's cooled down your fan doesn't unlock and you start losing air pressure when your engine coolant temp has returned to a normal range, then yes, I'd suspect your fan solenoid is sticking and leaking air.

thanks it does work correctly in the morning when I start the truck up the fan engages and then eventually shuts off and then while I’m driving down the road it’s fine I cannot hear any air leaking anywhere

[JAsaro]

(11-11-2020 )Mattman Wrote:  So do you have an air leak?

Can’t hear air leaking anywhere But I am assuming I do have an air leak because as long as the fan is going at idle I’m losing air pressure

[JAsaro]

(11-11-2020 )Coronado126 Wrote:  On big trucks, air is used to release the fan clutch and turn it off.

If your air pressure goes below 100 psi your fan clutch is supposed to "fail on" and lock so the engine can't overheat.

I'm losing some of the context of the problem from your post, but from I understand what you're saying, you don't have a fan problem per se, you have an air pressure problem somewhere else on the truck and you're noticing the fan staying on because it's the loudest part.

Now, if your fan kicks on like normal when your engine starts warming up, and then after it's cooled down your fan doesn't unlock and you start losing air pressure when your engine coolant temp has returned to a normal range, then yes, I'd suspect your fan solenoid is sticking and leaking air.

I am assuming I have an air leak because when the fan is engaged at idle IM losing my ear pressure

[Rawze]

* crank truck and let it build up air to 100% + fan is disengaged.

* switch off key and as soon as ngine stops turning, switch key back to run position.

* Engine now stopped, key in run position in dash, check by hand to see if fan spins freely. Also check clutch and solenoid for air leaks while it is still able to spin freely.

[JAsaro]

(11-12-2020 )Rawze Wrote:  * crank truck and let it build up air to 100% + fan is disengaged.

* switch off key and as soon as ngine stops turning, switch key back to run position.

* Engine now stopped, key in run position in dash, check by hand to see if fan spins freely. Also check clutch and solenoid for air leaks while it is still able to spin freely.

Thank you I’ll try that tonight when I get home

[JAsaro]

(11-12-2020 )Rawze Wrote:  * crank truck and let it build up air to 100% + fan is disengaged.

* switch off key and as soon as ngine stops turning, switch key back to run position.

* Engine now stopped, key in run position in dash, check by hand to see if fan spins freely. Also check clutch and solenoid for air leaks while it is still able to spin freely.

Did as you said and I can’t hear any air leaking anywhere it started to rain so I’m going to spray it with soapy water tomorrow