| How can I tell if my fan clutch is working? [message #89981] |
Sat, 26 June 2010 08:58  |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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I have never heard my fan go On or Off, and my temps never go above the low 180's (180 thermostat).
When I accelerate from a stop though it does sound like a jet though so I'm wondering if my clutch is stuck ON? However with the engine off the fan will turn fairly easy by hand. With the engine compartment open, I can feel it moves a fair bit of air.
Looking at Gene's clutch test numbers it would appear though there is not much difference between On and Off.
Everyone talks about how much noise the fan makes when its engaged, and trying to talk while traveling is not that easy so I'm wondering if mine is On all the time.
Any way to tell?
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
[Updated on: Sat, 26 June 2010 09:00] Report message to a moderator |
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| Re: [GMCnet] How can I tell if my fan clutch is working? [message #89986 is a reply to message #89981] |
Sat, 26 June 2010 09:44  |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Get a cheap Lazar pyrometer and block the lower 1/3 of the radiator and test
drive.
Use the instrument confirm temp at the radiator on the driver side area and
at center.
On Sat, Jun 26, 2010 at 6:58 AM, Bruce Hislop <bruce@perthcomm.com> wrote:
>
>
> I have never heard my fan go On or Off, and my temps never go above the low
> 180's (180 thermostat).
>
> When I accurate from a stop though it does sound like a jet though so I'm
> wondering if my clutch is ON? However with the engine off the fan will turn
> fairly easy by hand. With the engine compartment open, I can feel it moves
> a fair bit of air.
>
> Looking at Gene's clutch test numbers it would appear though there is not
> much difference between On and Off.
>
> Everyone talks about how much noise the fan makes when its engaged, and
> trying to talk while travelling is not that easy so I'm wondering if mine is
> On all the time.
>
> Any way to tell?
>
> --
> Bruce Hislop,
> S. Ontario Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI and ESC.
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: How can I tell if my fan clutch is working? [message #89997 is a reply to message #89981] |
Sat, 26 June 2010 12:10 |
shawnee
Messages: 422
Registered: February 2004
Location: NC
Karma: 0
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| RF_Burns wrote on Sat, 26 June 2010 09:58 |
I have never heard my fan go On or Off, and my temps never go above the low 180's (180 thermostat).
When I accelerate from a stop though it does sound like a jet though so I'm wondering if my clutch is stuck ON? However with the engine off the fan will turn fairly easy by hand. With the engine compartment open, I can feel it moves a fair bit of air.
Looking at Gene's clutch test numbers it would appear though there is not much difference between On and Off.
Everyone talks about how much noise the fan makes when its engaged, and trying to talk while traveling is not that easy so I'm wondering if mine is On all the time.
Any way to tell?
|
The quick and dirty way to test is when the engine is cold. Just give the fan a quick spin. If it spins less than 1/8th revolution after you let loose, it probably is good. If it goes further it is bad and won't engage. If you can't move the fan, it is bad and won't disengage and runs all the time.
Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
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| Re: [GMCnet] How can I tell if my fan clutch is working? [message #90000 is a reply to message #89997] |
Sat, 26 June 2010 12:25 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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What Gene is saying is correct, but I feel to also check it by slightly
overheating it is another step needed to confirm its capability.
On Sat, Jun 26, 2010 at 10:10 AM, Gene Dotson <shawnee@charter.net> wrote:
>
>
> RF_Burns wrote on Sat, 26 June 2010 09:58
> > I have never heard my fan go On or Off, and my temps never go above the
> low 180's (180 thermostat).
> >
> > When I accelerate from a stop though it does sound like a jet though so
> I'm wondering if my clutch is stuck ON? However with the engine off the fan
> will turn fairly easy by hand. With the engine compartment open, I can feel
> it moves a fair bit of air.
> >
> > Looking at Gene's clutch test numbers it would appear though there is not
> much difference between On and Off.
> >
> > Everyone talks about how much noise the fan makes when its engaged, and
> trying to talk while traveling is not that easy so I'm wondering if mine is
> On all the time.
> >
> > Any way to tell?
>
>
> The quick and dirty way to test is when the engine is cold. Just give the
> fan a quick spin. If it spins less than 1/8th revolution after you let
> loose, it probably is good. If it goes further it is bad and won't engage.
> If you can't move the fan, it is bad and won't disengage and runs all the
> time.
> --
> Gene Dotson
> 74 Canyonlands
> www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
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List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: How can I tell if my fan clutch is working? [message #90033 is a reply to message #89981] |
Sat, 26 June 2010 19:08 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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If it roars all the time I would say it is bad. I had one fail this way. With the engine off it felt normal. If you have the stock gears (3.08) it won't be as noticeable as it would be with (3.70) gears. If it is loud at 3,000 RPM and the temp. is 180 my guess is you need a new one.
Roy
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: How can I tell if my fan clutch is working? [message #90052 is a reply to message #89981] |
Sat, 26 June 2010 20:03 |
midlf
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
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| RF_Burns wrote on Sat, 26 June 2010 08:58 |
Everyone talks about how much noise the fan makes when its engaged, and trying to talk while traveling is not that easy so I'm wondering if mine is On all the time.
Any way to tell?
|
For my fan clutch equipped vehicles when starting cold the fan will roar like a 747 taking off. This is because the fluid in the clutch has settled in the bottom of the clutch and engages the fan. A few moments after starting the clutch will redistribute the fluid to it's "cold" location, the fan decouples, and the roar subsides.
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
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| Re: How can I tell if my fan clutch is working? [message #90083 is a reply to message #90074] |
Sat, 26 June 2010 22:41 |
midlf
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
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Senior Member |
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| roy1 wrote on Sat, 26 June 2010 21:16 |
That is normal operation and lets you know it is operating. However my latest one is quiet from the get go but functions when it is needed.
Roy
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That's interesting to know. I wonder what may have changed in the design to eliminate the startup roar.
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
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| Re: [GMCnet] How can I tell if my fan clutch is working? [message #90245 is a reply to message #90217] |
Mon, 28 June 2010 07:29 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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Thanks.
I don't dislike Hayden fan clutches. GM, which doesn't seem to make
anything anymore, buy from Delphi, which repackages from some other
source. Pretty straight forward but gets pretty crooked when you
realize that the AC Delco HD fan clutches are subbed to Hayden which
subs to China. You don't know what you're getting anymore.
On Sun, Jun 27, 2010 at 8:30 PM, roy keen <roynpaula@charter.net> wrote:
>
>
> The one you don't like a Hayden but it is around 4 years old .it is a lot better then the previous number of Hayden's I have used. If I remember right a #2959 ?
> Roy
> _______________________________________________
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>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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