Cooling Issue While Idling

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Nov 7, 2012 | 10:19 PM

#16

JB-1

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From: Tustin, CA

Quote:

Originally Posted by 81ChopTop

A/C trucks usually have the "extra cooling" radiator and is wider than the non-a/c trucks, unless it was ordered with extra cooling with no a/c. There's two sets of threaded holes in the core support (drivers side), so if you are using the inside holes, it will be standard cooling, if you are using the outer set, it's the extra cooling radiator.

Looking at my radiator (picture seen below) I see what looks like a duplicate set of mounting holes on the inside of the radiator, so I think this means I have the large radiator. Is that correct? I also checked the fan and it is wiggling on the clutch and not on the pulley. So that sounds like good news to me. Between the bolts holding the fan to fan clutch and the bolts holding the fan clutch to the pulley I see what looks like a nut of some kind. Does that mean I have the screw on kind? I can provide a picture if need be.
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Nov 8, 2012 | 07:15 AM

#17

81ChopTop

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From: Wausau, WI

Looks like you have the bigger radiator. For the nut, I'd say the clutch is the thread on style. You could always post a pic of that just to make sure.

Nov 8, 2012 | 08:57 AM

#18

Galendor

Fleet Mechanic

Joined: Jun 2010

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From: North Carolina

Quote:

Originally Posted by Franklin2

Heater core being bypassed has no affect on the cooling system.

Dave, I think bypassing the heater core does have a small but detectable effect on the cooling system. I bypassed a leaky one in a truck years ago and observd that the needle on the guage was a little bit higher after that. Once I replaced the heater core, the temp went back down a little to its previous spot.

As you already of course know, bypassing the heater core reduces the coolant volume in the system, and reduces the radiative surface area of the cooling system. It just makes sense that this might have an effect, even if only small, on the cooling capacity of the system.

Nov 8, 2012 | 01:04 PM

#19

JB-1

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From: Tustin, CA

Quote:

Originally Posted by 81ChopTop

For the nut, I'd say the clutch is the thread on style. You could always post a pic of that just to make sure.

I like to be prepared and do my homework before I tear into something, so here is the picture of where the fan clutch attaches to the pulley.

Nov 8, 2012 | 02:24 PM

#20

1986F150six

Lead Driver

Joined: Jul 2009

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From: Sheffield, AL

Good! The nut you are looking down on is the nut which holds the fan clutch to the water pump shaft. Be sure to keep the belts on as you loosen the nut or the whole assembly will spin as you try to loosen the nut. [In retrospect, you will not need to remove the belts as long as your water pump is good]

Remember, the nut has reverse threads, so it is NOT "righty tighty & lefty loosey". Looking as the photo is oriented, turning the nut clockwise will loosen it. Depending on how tight your v-belts are, you might try squeezing the belt(s) by the alternator to help hold the pulley stationary.

Good luck!

Nov 8, 2012 | 03:54 PM

#21

81ChopTop

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From: Wausau, WI

^Good advise there. Just don't put a vise-grip on the pulley. A previous owner did that to my truck, and it chewed belts like you wouldn't believe. Had to replace the pulley and all is fine again.

Nov 8, 2012 | 08:13 PM

#22

Galendor

Fleet Mechanic

Joined: Jun 2010

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From: North Carolina

You need a way to hold the part that the fan bolts on (with 4 small bolts) still while you loosen that large central nut.

There is a "special" set of thin wide-mouth wrenches specific for this task. If you don't have those, then I believe it is possible to hold the fan portion steady with a long box end wrench, perhaps with a piece of extender pipe, over one of the small bolt heads but positioned so the the arm of the wrench also braces against one of the other small bolts. Kind of hard to explain. When I reassembled mine, I used copper anti-sieze on the large central bolt so it would come off easier in the future. I may be recomended that you let some thread penetrant soak in first before trying to loosen it. If it loosens suddenly, you are in a position to really crack some knuckles or worse, so wear leather work gloves.