I know, right?!
The only thingn that I can think of is that once you install it and then drive it because the fluid is not "settled" in one spot but dispersed all around once you start the engine it just gets stuck in the crevises...hell I dont know man, I'm just guessing here!!!
But it is very crazy, things I never knew.
The only thing that I can compare it to is when you move a refridgerator, you have to let it sit level for 24 hrs so all the compressor oil settles back into the compressor but how does it know where the compressor is?
Makes my head hurt.

 

Save some money and get one of the imperial fan clutches
Imperial #215157: Will Probably work fine.
Imperial #215158: Heavy duty and sounds like an airplane at first.

About $65 at Advance Auto.
With those you can also use the metal imperial fan.

edited for clarity

 

Is the Imperial fan just a aftermarket replacement fan? Or is it a flex fan?

 

that part number is a fan clutch

 

Ok, thank you.

 

The part numbers I provided are the fan clutches. I didn't have the actual fan PN handy. Let me know if you want it.
It's a metal replacement fan. Defender drivers use them, but they won't fit a Disco unless you've installed the aftermarket clutch. The Imperial clutch extends the fan closer to the radiator.
So many reports of the plastic fans disintegrating and taking out the radiator made me decide to switch to the metal fan after I replaced my clutch with the 215158 clutch.

 

Well my fan is working again right now so I'm not to worried about it.
It is going to be colder this week but I am still going to use my scanner and keep and eye on the engine temp.

 

Ok, so here is some more info on this.
I have been chasing a rough idle, no codes but the idle was kinda rough, not bad but enough that it bothered me.
I did 2 complete tune ups, still there.
Tried different brands of gas, still there.
So now that my clutch fan is working again my rough idle is GONE, I have to look at the dash to make sure that the truck is still running!!
Is this a engineering thing to help smooth the engine? Is this just a high mile thing? Is this all in my head? Am I just that crazy?
I mean what the hell?

 

save money and get the oem replacement part with right size bolt holes.

Hayden 2991

http://www.summitracing.com/parts/HDA-2991/ $57