Awesome video! Probably the best explanation anyone could possibly do on a fan clutch. Thank you for taking the time to make this video.

Thanks for this post. Great explanation. I had no idea how they worked or really the complete function until watching your video.

Thank you for the explanation how the fan clutch works, I was wanting to know how it did!

Great dissection of a mechanical fan clutch. Learned a lot.

I've been reaching for 35 years that's the best explanation I've ever f****** heard or seen of could work

My Jeep didn't come with the factory tow package. It has an electric fan for the radiator, but I need to add the mechanical fan with a clutch to add extra cooling. Thanks for the explanation. I had no idea how it worked. Great videos.

Hey Brian, this was such a cool video! Happy Fathers Day Looking forward to watching your other channel Aloha and take care

@briansmobile1 the fan hub you cut up should have had silicone oil in it, if it's empty, that's why there's no resistance in it and it doesn't work. If you open the new one, it will have around 30-60ml of honey consistency silicone oil in. Different hubs and engines require a different oil weight, i Just put 36ml of 10,000mm2/s in my hub. Excellent video and explanation but it's missing a vital part! Cheers!

THANK YOU it has been killing me wondring how those work for a while now

Happy Father's Day! Great video!

Thank you for the video brian

Absolutely fabulous ! Great Vid and subject matter. Thank You again .

Great video. My Jeep is having an issue with the clutch fan I believe. Keeps nice and cool on the highway, and on long straightaways...then in traffic it runs a bit hotter without overheating. I didn't realize that the spring in the middle was a sort of 'thermostat". I figured they just ran on centrifugal rotation based on engine rpm.

Very cool Brian! I was actually quite interested in how these worked, wanted to try to add an override switch to them but looks a little impossible. Either way you make really great and informative videos! Keep it up. Btw, You remind me ALOT of my oldest brother.

Love the videos happy fathers day!

If I put higher viscosity fluid inside would the fan be running all the time? I just want the fan to spin louder at low speeds for the cool rushing of air sound like in big diesel trucks.

Thanks for the vid, I learn something new today 😁

Nice tear down.

What would cause them to come on too early or be locked up all the time. I’ve tried 4 different ones... the engine and radiator temp are at 205.

Nice video happy belated father's day to you too

Very goo explanation good job cutting that one apart

Hey Brian- this is a great video explo-tionation! I am about to buy a 7 blade Mopar fan with a clutch. This is for 1968 383 motor and as you can imagine it's getting harder to come by. So my options are limited. How can I be sure that I am buying something that is good quality and not to used up AND how hard would it be to replace the worn out portions of seriously old internals of the clutch?

Excellent instruction.

Hi Brian, I have 95 crown vic and my fan is always on, hot or cold. It has the same type of clutch as in your video. Is this normal and Can these clutches lock up?

Great informative video thanks

Thank you. Exactly what I needed to know.

Thanks for showing this video.

Great explanation of how a fan clutch works. If you still receive notifications from this I have a question. I had the timing belt and water pump replaced is it true that they should have replaced my fan clutch when doing the water pump? I read that the fan clutch will wear the water pump quickly on my 1988 Toyota truck with a 3.0L V6 if it was not replaced.

very good information thanks you

I have a 96 nissan truck and the parts both old and new look exactly like what I have. the old for sure and the new I picked up a O'Reilly's and is a IDC. my old one was doing the opposite. It was locked up and even though I could get it to turn by hand there is a point that it just sticks. now that I know there is no fluid in there maybe it could be cleaned up. I don't know. but I am curious how the new one has been working. I had about a month where I didn't notice anything and the fan was turning but no issues. It was a month later and I didn't even think about it being the Fan Clutch because it was new. But evidently mine is not engaging when it needs to and I heated is up to 220 and it is still the same. but when it is on the pulley and the Water pump *waterpump is good, when it is there and I suddenly hit traffic and it needs to cool things down you can hear it getting wobbly and just enough time to pull over because it reaches out and nicks the radiator. The fan blades that are attached to the Fan clutch move from that wobble just enough to nick the radiator and lose your fluid and get a tow home. I chased so many other things and I could not believe it when i realized the new one I bought was not working correctly.. So I am just curious if after some time did yours do good? I think mine was made by IDC for O'Reilly's. ayways, thx, kinda interesting coincdence and I am hoping the next one I get is not messed up. definitely will test it beofore I install it so I don't nail another radiator. that makes 5 aluminum and my OEM nice heavy duty one all from this crazy part and that no one thought it could be the culprit.

Great video. Thanks

Thanks your awesome your very good machines to do that cutting with great detail explanation keep it up 3 thumbs up

The BEST video seen.

Allot of info!! Nice visual

thanks for teaching us.....

Makes me think with all that work into it how can they sell them for next to nothing haha

hey brian. im just curious. where did you go on your trip if you dont mind sharing. wherever it was it was beautiful. reminded me of bermuda

Great info.

Excellent video again!I still watch your videos as a self employed mobile mechanic!ive learnt alot from you,keep up the good work dude!

Nice video

thanks for sharing !

I think you got it wrong. According to my college book that spring just opens a hole for the fluid to flow. I think your old clutch just lost all the liquid that is why is dry. The new one got fluid inside.

Yeah I always wondered how those things worked like without wires from the ecu telling the clutch to engage or without having hot coolant flowing into the clutch to engage the sping that reacts to temperature. (I'm like I know they have a spring that responds to temperature but how do they know the temperature of the engine if they don't have coolant flowing into them to engage when the coolant is hot) The thing I still don't get is how do those clutches know to engage when the ac is on without any type of wires going to it???

Came for the fan clutch, stayed for the jet, liked for the dive footage :D

Thank you. You are OK

Awesome!

Very Rusty Spring: The other day I was towing our camper. OAT was approx 65*F. ECT went up to 238*F. No fan engagement at all. Clutch has resistance but I was thinking the fan clutch spring was very rusty like sandpaper and binding up. Thinking possibly the spring is not rotating.

Cool vid

Good video. No fluid/gel in there?

do they always spin freely when they go bad? Or do they also lock up or get stuck half way? I guess what I'm trying to ask is can they cause a overcooling scenario at start up and idle when the engine is just started?

Question. Can a fan clutch turn either way or they are meant to turn either CW or CCW?

I don't understand what this spring does. How can that lock the clutch?

Tank you my frind

Brian. Do you prefer an electric fan or a mechanical/clutch type?

Thanks for the video Brian. So there’s absolutely no fluid in this type of fan clutch? I think this is what I have on my 2003 suburban

What's your other channel

I recall in the 70s n 80s...we would run a bolt thru the clutch to make it lok up....im having trouble w my 2014 tacoma.....its running 2014 on hiway...i was able to put my glove on and grab the fan blade and stop it from spinning😲🙈😲🙈😲

I had a tractor with failed fan clutch this spring, supplier did not have a new one so they suggested just to weld shut moving parts together so it would be constant fan on. At least tractor could work in the field...

Nice video; But you got that backwards: The feed hole (slot) is COVERED when cold, opens when hot... (since you've cut away the case, you have the bi-metal spring out of alignment). Also, this IS a fluid clutch, that moving vane releases the fluid into the clutch fins. And the internal fins are NOT for heat transfer, they are there for the viscous coupling of the two plates... The spring does NOT force them together. The fluid must have completely leaked out, or you washed away what was left of it. But VERY GOOD presentation... Mr K L

I definitely understand the concept of the fan clutch. I don't understand why there is any resistance at all when the clutch is at room temperature and the fan is not needed. At room temperature, the engine/radiator would be considered "cold," and the radiator would not require any cooling air from the fan. So at room temperature, there should be NO resistance in the clutch so the pulley can spin freely without resistance from the fan (with a cold engine, the fan would do nothing but suck engine power and lower efficiency). But if the clutch has resistance at room temperature, that means the fan will be turning when it's not needed. It seems to me that the clutch should be completely disengaged when the radiator is cold. Then, as the radiator gets hotter and hotter, at some predetermined temperature the bi-metal spring would turn enough to engage the clutch and spin the fan ONLY when additional cooling is needed. What am I missing?

Does it matter which way the spring is wound?

Very cool... errr no pun intended. I really wish we had access to the internet when I first let my curiosity about how things work, get the best of me... luckily, it was just a few black fingernails and lots of 4 letter words and nothing permanent

You just nid to clean and refill with new silicon oil. The one you open is compltelynm dry

Ever since these things first appeared back inn the 80's or so I was told a honey like viscvous fluid was used ....I believe when they wear the Viscous fluid leaks out and they can no longer work to put it simply...Ive grabbed and stopped many a fan blade on a hot engine while the clutch was freewheeling and the engine idleing with my bare hands showing off to my fellow mechanic friends when I was a teenager , I would let the back side of the blades strike my fingers and slow it down and then Grab the fan and hold it still for a few seconds while the engine was running... LOL

Time for a new Fan Clutch 1:07

Imports and domestic vehicles going back into the 80's all had a silicone fluid fill via a screw on the engine side. The closer the plates you exposed in the cut-a-way simply expose where the fluid is held. This fluid become thicker and thinner in viscosity just like most fluids, even oils as temps change, but it produces a drag between the drive and driven parts the control the fans speeds. Yours like everyone else simply failed as it developed a leak. The silicone formulated and injected is gone leaving no means of moving the fan to match or couple speeds with the circulation pump or fan block as some designed. They all had silicone fluid inside then between those cavities and gone because of a leak, it simply freewheels. As for overheating at highway speeds, they normally are along for the ride and don't pull air thru the A/C condenser or radiator. Flushing the radiator core to have no insulation debris separate the fins & outside air or and engine problem was most likely you root cause of overheating under those conditions as the fan clutch had fail over winter or months earlier. The pressure cap holds 15-17 PSI on the coolant. Each 1 PSI raises the boiling point 3 1/4 degree F to 264 degrees F roughly (Yours may vary) but the clutch was not the problem at 50 MPH - 75 MPH with or with out the fan clutch functioning. DK, ASE master tech since 78.

I always thought it had fluid in them like a torque converter

So this is different from a viscous because them ones spin and disengage fan blades when cold watch the the manufacture one above this don't confuse people with the difference none are supose to spin u till rad is hot

tried 3 of the new junk fan clutches from china and my truck sounds like an airplane cold or hot. off and on all the time. new ones are cheap garbage. went to the junk yard with an original clutch for $30. no problems.

Just found out it was fathers day....

I hate mecanical fans, whenever mine turns on my pickup sounds like a semi trailer :(

Poor engine... Those clutches are reliable, but go tear out an electric fan from a scraped ford taurus or something. Tiny engines suffer quite a bit (or as much as alternator strain) and that pully puts too much torque on the pump behind it, causing your whole engine to heat up and strain from being heated up and straining.....