How Does a Viscous Fan Clutch Work?

Learn what makes a viscous fan clutch operate. Detailed animations show internal components.

[gregculverwell]

That explains why when I 1st start my car in the morning the fan runs for about 30 seconds & then disengages. Obviously the fluid has been trapped & has to flow back to the reservoir 1st.

[thatkyleguy]

Well I'll be damned. Always been curious about this and now I know. Thanks a bunch!!

[babyhominid]

One of the more amazing overlooked parts.

[TheMrDarius]

I knew that it had its own fluid that self contained but I never understood the principles in which it acts. Very simple system. No wonder fan clutches last for years before needed to be changed. Still going to convert my Tahoe to electric fans but now I understand how the mechanical clutch works. Thank you for this. Very informative.

[henryham]

These is the best description of how the fan clutch works. Thanks for explain it.

[busterscrugs]

I've always wondered how the viscous fan clutch on my E39 worked, this video was quick and made it simple to understand, thanks!

[khaosnd]

This technology is actually quite genius. I replace my electric fan because there were too many problems with one of these clutches and it has not failed me once so far

[MrBigR]

I used one Kit Masters Horton Fan clutch rebuild kits on my 3406e Cat from Southern Electric in Conley Georgia & that was a beautiful kit & saved me a nice chunk of change too🥰👍🏿 Shout out to Dale at J&J truck repair for telling to buy it there & then he installed it for me for a great price! All together buying the reman plus install still came in under the price of a new one that wasn't a Horton Clutch! I get all my starters & alternators from Southern Electric & that's not often because they rebuild them to last👍🏿

[thepeople]

Impressive engineering for a $25 part.

[garyr]

That's a very comprehensive explanation, simply put yet well said.

[rorypenstock]

How does the fluid flow "uphill" or against centrifugal force in the return lines?

[Legendary]

This is absolutely an amazing explanation. All explained simply without unneeded details.

[qtztzgw]

Also worth mentioning these things last forever. Ive rebuilt several engines in vehicles from the 70s 80s with over 150k miles. Have not once replaced the fan clutch

[mikeking]

I had no idea how these worked. The best I could come up with was so kinda magic. Thanks!

[kritikprasad]

Mate, this is one of the best educational videos I have seen. Well done, animations were amazing!

[saltysteel]

The Humvee has a hydraulic activated fan. An extra hydraulic line comes from the power steering pump and goes to a solenoid. When the solenoid opens the hydraulic fluid pressure flows to the fan clutch and engages the clutch. It's really interesting and pretty simple.

[irishlad]

Thank god an actual video that exspains how they are supose to work I hope ford's have watched this Mr Ford man there not supose to spin when radiator is cold ie engine coolent temp passing through rad and when they roar when cold and spin when cold there goosed I wished all the deisel engineers and garages would have watch this it would have saved me 5 rads and stats and pumps

[lewiemcneely]

never had any trouble with type of clutch but really got into a crimp with a newer air operated one. Good explanation and Thanks!

[eprofessio]

I just drill holes in the clutch, run a tap and then insert some bolts. When you live in the desert Southwest it seems okay to have the fan on all the time after it breaks anyway.

[El]

Thank you. Clear and to the point. Nice job.