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Is this what I think it is? hydraulic serpentine belt drive fan clutch? Fort Lewis,WA

They are hydraulic. I have 8 like that except they are v-belt.
 
The newer 6.5's the military uses are all using a serp belt.

Most of the motors you are finding are from the old chevy/gmc cutv and the original hummers.
 
Ahh, thats what you were keying in on, it is on a serpentine pully rather than V belt.

Exactly.

This would solve the "fan clutch thermal spring delay" and heating of the engine to and over 215 when you stomp it for a hill. If you can stand 100% fan or no fan at all...

Can we obtain these parts? Someone made them or makes them.

I don't see the Hummer electric ECT pressure switch or power steering pump tap that big of an issue.
 
Good point. How hard would it be to use that? Perhaps even an in cab lever could create enough hydraulic pressure to engage it?

I would love ALL OR NOTHING when it comes to fan. Absolutely would love direct control of the fan.
 
The serp and v-belt clutches are the same. You need about 100psi to release them, 125psi would be better.

They run off the return from the steering box to a relief valve/solenoid combined together. With the solenoid closed it stops the return to the reservoir, pressure builds on the return line to around 125psi opening the relief valve, the 125psi releases the fan clutch. When solenoid opens it dumps the return to the reservoir, causing the fan clutch to engage.

I never tried to bolt one to a stock waterpump. On the HMMWV the pulley bolts to the water pump and the clutch bolts to the pulley with four bolts.
 
How about electric fans ?

Yet to be proven effective when needed while going highway speeds. Most vehicles dont need fan assistance at speed, but these 6.5s do sometimes when towing and going uphill and trying to maintain speed. I would not trust an electric in a tow vehicle or something that gets loaded much and drive up mountains and such. If the truck is only for commuting or in town low speed stop and go pulling then electric would work fine.
 
The serp and v-belt clutches are the same. You need about 100psi to release them, 125psi would be better.

They run off the return from the steering box to a relief valve/solenoid combined together. With the solenoid closed it stops the return to the reservoir, pressure builds on the return line to around 125psi opening the relief valve, the 125psi releases the fan clutch. When solenoid opens it dumps the return to the reservoir, causing the fan clutch to engage.

I never tried to bolt one to a stock waterpump. On the HMMWV the pulley bolts to the water pump and the clutch bolts to the pulley with four bolts.

Sounds fairly do-able then. You could then wire the Solonoid to a switch for engagement? (t-stat type or manual?)
 
Edit: Entire diagram with pulley options:
http://www.tpub.com/content/hummer/TM-9-2320-280-24P-1/css/TM-9-2320-280-24P-1_112.htm

parts:

Serpentine Pulley:
http://www.real4wd.com/zedSuite/catalog/partdetail.aspx?partno=RCSK18221

thumbnail.ashx


Clutch:
http://www.real4wd.com/zedSuite/catalog/search.aspx?keywords=12339407

Other parts like the switch, hose, and delay unit are on here...
http://www.real4wd.com/zedSuite/catalog/partdetail.aspx?partno=12338603
http://www.real4wd.com/zedSuite/catalog/partdetail.aspx?partno=5583177
http://www.real4wd.com/zedSuite/catalog/partdetail.aspx?partno=12338599
http://www.real4wd.com/zedSuite/catalog/partdetail.aspx?partno=1059-06607-01

How to hook up, 24v solenoid I bet.

http://www.tpub.com/content/hummer/TM-9-2320-280-24P-1/css/TM-9-2320-280-24P-1_534.htm
 
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Thats the normal Hummer fan clutch setup. Bobbiemartin had or has one for sale here
http://www.thetruckstop.us/forum/showthread.php?25018-Lots-of-6.2-6.5-Turbo-parts-for-sale

The one I have is for the 4 V belt pulley. I haven't looked at it lately, but I think the fan clutch has a different bolt circle than the regular serp pulley so you would need the pulley made for this clutch. It looks to be the same clutch for both pulleys, so I guess rotation doesn't matter?
 
yeah but the stock 6.5TD serp pulley is pressed on.

That would be the 4 bolt ones are "rusted on"... The latest screw on clutch and water pump pulley may be pressed on as they look to be sold that way.

All my 1993's pulleys fell off the stock and HO water pumps when I pulled the clutch.
 
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