Replacement Heater hoses

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Atekido

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Are these 2 red hoses called Heater hoses? They are going from the Radiator back to the passenger side firewall. My grandfather just called them heater hoses and he said their sizes are not the same between them in terms of the opening diameter on the ends. He thinks they have been on there well over 10 years and recommended that I get them replaced.
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77 K20

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Yep- those are called heater hoses. They bring hot coolant from the radiator to the heater core.
 

AuroraGirl

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Are these 2 red hoses called Heater hoses? They are going from the Radiator back to the passenger side firewall. My grandfather just called them heater hoses and he said their sizes are not the same between them in terms of the opening diameter on the ends. He thinks they have been on there well over 10 years and recommended that I get them replaced.
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Inspect them depending on how your truck was plumbed it could t back into the rad. Your hoses domt look bad. How do they feel. Are they rigid, rubber not deteriorated?
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mine are red
 

75gmck25

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One hose is 3/4” and the other is 5/8”. I’d have to verify for sure which one is which, but IIRC the 5/8” is the one that connects to the fitting on intake.

it would be good preventive maintenance to replace them if they are old. Or at least buy replacement hose and keep it on hand for repairs when one fails. They used to sell the replacement red hose in plastic packages at the parts store, but I think most stores now sell bulk black-colored hose.
 

Powerhouse Ranch

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my two cents, if it works, let it be. i went to replace a leaking powersteering hose (factory) that had a slight leak on it and blew the new line due to defect. got another one for free as replacement, also blew. Ended up putting the factory leaky one back on. I have since tracked down a trustworthy hose but its only a backup.

SO

Don't open a can of worms if it doesn't need to be / works just fine. Factory or older parts are better than the junk nowadays
 

AuroraGirl

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One hose is 3/4” and the other is 5/8”. I’d have to verify for sure which one is which, but IIRC the 5/8” is the one that connects to the fitting on intake.

it would be good preventive maintenance to replace them if they are old. Or at least buy replacement hose and keep it on hand for repairs when one fails. They used to sell the replacement red hose in plastic packages at the parts store, but I think most stores now sell bulk black-colored hose.
That size orientation matches my setup. The big hose goes to pump which is output I think and intake is the return. The radiator hookup would be a tie into the output? Idk man I just work here lol
 

Atekido

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They feel fairly rigid but still pliable, and no signs of cracking. I think he was skiddish of them because he had to replace them I guess 10 years ago when the originals went bad or something.
 

AuroraGirl

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They feel fairly rigid but still pliable, and no signs of cracking. I think he was skiddish of them because he had to replace them I guess 10 years ago when the originals went bad or something.
Originals did a hell of a good job then. 10 years is a whole, sure, but I ask this: how clean is your coolant, amd do you have a distilled and antifreeze mix with nothing else in it?

maybe tap water is in there or additive or some kind? Any running on outsideA
.? A
Anything other than perfect mix and no special things that could ding the life I would leave them.
 

Atekido

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I believe its a mix of distilled and coolant. but being in Nebraska vs Arkansas i will have to drain it to put in some that can hold up against nearly -30 temps.
 

AuroraGirl

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I believe its a mix of distilled and coolant. but being in Nebraska vs Arkansas i will have to drain it to put in some that can hold up against nearly -30 temps.
Two ways to get that, because the truck has a lot of cast iron and isn’t made like a modern car…. You have more volume and bigger passages and lower pressure. Not sure what the flow compare to modern vehicles, but if your truck has a good time cooling, I would suspect a 60-65 % mix could be done but I would do 55% antifreeze and distilled on a clean system… but if you feel that isn’t enough, I would do heating with a block heater on coldest days before I would change the cap or the mixture further

14 , 16 psi? I forget what we are using on squares. Domt exceed that if you don’t have to , but you could be safe with a psi or two.. if you have good seals and nothing barely hanging on
 

75gmck25

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Most of the older trucks I’ve seen (like my ‘75) have the heater return hose connected to a fitting on the radiator, but some have it running to a nipple on the water pump. I’m not sure why GM had two variations.

I bought a new Champion aluminum radiator from Jegs and it has the fitting for the heater return hose.
 

Atekido

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so far cooling has been no issues minus sitting in traffic a few times on the drive back it was a heat index of like 110 and the temps got to what im guessing was around 200-205ish. it never made it to the halfway mark of 210.
 

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