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Discussion Starter · #21 ·
Ok guys, waited for it to cool, took the plug out, a ton of air came out I filled the rad until it was coming out of that 3/8” plug, reinsterted the plug, then I filled the radiator and I got another gallon in it. I took it around the block, still getting very hot. Any more ideas? Should I repeat the procedure? ALSO is this white stuff around the manifold bolt anything to worry about?
 

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Ok guys, waited for it to cool, took the plug out, a ton of air came out I filled the rad until it was coming out of that 3/8” plug, reinsterted the plug, then I filled the radiator and I got another gallon in it. I took it around the block, still getting very hot. Any more ideas? Should I repeat the procedure?
I would at least 1 more time, and like I mentioned maybe the fan clutch is bad.
 

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Best way when it cold spin it then spin it when the engine is up to temp, should be harder to spin when engine is hot. Also the fan will be louder when it's good and engaged.
 

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If you're actually pegging the gauge you should be steaming out coolant really bad.

Also, if you're getting that hot your radiator fan should be screaming (if the thermostat is working)

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Discussion Starter · #26 ·
I stopped it before it pegged this last go around and there was steam coming from the rear of the motor and somewhere near the front. But I grab the upper rad hose and it’s not hot. Is that normal? By me saying that now I feel like it’s not actually getting that hot
 

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Sounds like your thermostat isn't opening.
 
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You can wack the thermostat housing with a hammer sometimes to help it break loose, but might be worth changing it. Hand tools and rtv are all you need to do it. Most auto parts stores carry them on the shelves.

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But not all brands are good, a Cummins is the best way to go. I have heard some have had good luck with NAPA brand.
 

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Discussion Starter · #30 ·
So a thermostat is more than likely why the upper rad hose is barely warm but it’s overheating? Is that a symptom? I just ordered one
 

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The thermostat isn't opening so the coolant doesn't flow out of the engine so it can cool.
 

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If you only made a couple of miles then the gauge pegged, it is bad or you have other issues. Mine takes several miles to get the thermostat to open.
With the rising fluid in the funnel that may just have been normal expansion as the coolant heated.
Not familiar with these vehicles, is the heater circuit constant flow or have a shut off valve? If fitted with a valve it needs to be open when trying to get air out of the system
 

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If you only made a couple of miles then the gauge pegged, it is bad or you have other issues. Mine takes several miles to get the thermostat to open.
With the rising fluid in the funnel that may just have been normal expansion as the coolant heated.
Not familiar with these vehicles, is the heater circuit constant flow or have a shut off valve? If fitted with a valve it needs to be open when trying to get air out of the system
Vacuum controlled shutoff for the heater core. However, it's in its own world. Coolant will circulate just fine without unlike a lot of other designs.

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Some Cummins thermostats didn't have a jiggle pin, since the engine it was supposed to be installed in and had other means to purge air... I found this out when I grabbed the 180° thermostat out of my 2009's glovebox and stuck in my '92. Same symptoms as you and it was just air!
 

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I did not read all posts. but anser si simple. You have to run it long enough for the thermostat to open and then it will clear the system of air. Once open keep filling slowly until full. A little raise in rpm after up to operating temp will help. Warm up with cap OFF.
 
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