Collapsed upper radiator hose

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fast 99

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Like that idea. I think @Ricko1966 had recommended putting an aspirin or Tylenol tablet in the thermostat to prop it open for complete circulation before it dissolves and goes away. I haven’t tried it but sounds like a neat trick

Had Tylenol in the toolbox will those work? lol Anyway use whatever method is easiest to vent the air. There will almost always be a little residual, usually need to add coolant after first heat cycle or 2.
 

squaredeal91

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Might not be the best practice nut I allot of times drill a small hole in my thermostat to bypass a little and I've had no issues doing it this way for many years.

Side story: In HS a friend removed and drilled his thermostat 3 times to adjust his engine temp to perfection. I'm not saying he drilled 3 holes. He drilled one really small hole increasing it till the gauge showed perfect. Was also the same kid who cleaned his engine with Qtips and rubbing alcohol lol. We called him Mr. Clean
 

Catbox

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Sounds like you already have a thermostat similar to the one that I recently purchased.
It has the little brass jobbie in a hole that will let the trapped air escape in the case the stat is not open.
When water pressure is present, brass jobbie is pressed against the stat and closed off.
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Engine side of stat and you can clearly see the brass button that easily moves around.
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Housing side and you can see the top of the brass button and its ability to release trapped air.
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If it were mine, I would look at and make sure the overflow tank and hoses are able to flow back and forth for water expansion and contraction.
 

George915

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Everything seems to be working fine right now my thermostat is similar just different manufacturer. Hose isn’t collapsing and overflow tank is operating as it should. Now I’m just trying to get my TV cable adjusted properly. Ha
 

Bextreme04

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The thermostat hole or bobber really isn't necessary on most squarebodies because the heater core acts as a vent for any air in the engine anyways. The way that the heater system runs allows the pump to vent all the air out of the engine through the heater core and out to the radiator. You will get a small burp of air out of the upper radiator hose when the thermostat opens, but that should be it. That's why on a fresh engine, you should fill the radiator all the way up, then leave the cap off and start the engine. Top the coolant off with the engine running and let it run until the thermostat opens and you get another burp. Then top the coolant off again. Now you can shut the engine off, install the cap, and fill the overflow to about midway between hot and cold full. Come back the next day and top off to full cold.
 

fast 99

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because the heater core acts as a vent for any air in the engine anyways.

Could you explain further. Depending on configuration, isn't it possible air could still trapped in the system? The return hose goes back to the water pump in many cases. The air is now in the block and could uncover the stat?

Systems that have returns back to the radiator right tank, agree.
 

Bextreme04

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Could you explain further. Depending on configuration, isn't it possible air could still trapped in the system? The return hose goes back to the water pump in many cases. The air is now in the block and could uncover the stat?

Systems that have returns back to the radiator right tank, agree.
It's returning the air to the return side of the pump... which is also full of coolant from the radiator. It's not going to allow a bubble of air to sit in the intake under the T-stat. It's not quite as good as having the return into the radiator, but the return to the pump is really only on the early 70's ones and easy enough to retrofit. I run all mine to the return side of the radiator for that reason.
 

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You need a new radiator cap. Also, see if you can buy hoses with a spring inside. That spring prevents collapsing.

J. B.
Just replacing my hoses. Do the normal spare part hoses come with a spring? My old lower hose is pretty soft, are the spare part hoses stiff enougn normally? Is spring needed if engine revs less than 5600?
 

Sad Sack

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Had Tylenol in the toolbox will those work? lol Anyway use whatever method is easiest to vent the air. There will almost always be a little residual, usually need to add coolant after first heat cycle or 2.
I tried Vicodin and now my truck is constipated, arghhh.
 

Sad Sack

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The old radiator flush kits worked great for filling a block up, fill with water at radiator then add coolant till it showed green at the heater hose tee. 50 / 50 outcome every time.
 

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Take the radiator cap off and run the motor until it gets to operating temp (10-15 minutes). Add your 50/50 or water until the radiator is full. Put the cap back on and grab a 6-pack.
 

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