304 V8 coolant help

[1976Levis]

So I changed out all out my hoses. Heater, bypass, upper and lower radiator. filled the radiator back up let it run and let some air escape. After taking it out for a 1/2 hour today I checked out the hoses when I got home. all of the top hoses were smoking hot except for the lower radiator hose. it felt warm and that was it. After it cooled down, I opened the radiator and squeezed on all of the hoses. I was able to move coolant by doing that. I even loosened the lower hose to see if there was air stuck in the hose. coolant did come out of the lower radiator port and the water pump port when I loosened the clamps at the ports. When driving today the stock gauge was still in the green at about 3/4. Your thoughts? Bad water pump? Thanks for your help in advance.

 

[Torxhead]

A bad water pump will have a bad bearing in it. You can check this by rocking the fan back and forth, there should be no play at the shaft going into the pump. Usually a bad water pump will leak out of that front bearing or thru the weep hole underneath that bearing housing. It that is not it you are just going to have to do some research and find out where your leak is.

 

[hdgapeach]

Thermostat maybe???? If the thermostat is sticking, it'll give you different radiator hose temps (top to bottom).

Cheap enough to replace and you can check the function of it with a pot of water on the stove before you install it.

 

[Hedgehog]

I always change the thermostat when doing a major hose change.

 

[jdcaples]

Could a failed head gasket cause a blockage to explain this?

I've seen air intrusion from a failed gasket happen, but I don't know if a piece of the gasket could block a coolant passage-way.

-Jon

 

[mtnwhlr]

I don't think so normaly is the other way around you have coolant leaking into the motor not blocking the flow.

 

[Lumpy Grits]

When was the last rod-out done on the radiator?
Hint-Don't use 'tap' water on the refill-Distilled water only, with antifreeze.
LG

 

[DHugg]

So I changed out all out my hoses. Heater, bypass, upper and lower radiator. filled the radiator back up let it run and let some air escape. After taking it out for a 1/2 hour today I checked out the hoses when I got home. all of the top hoses were smoking hot except for the lower radiator hose. it felt warm and that was it. After it cooled down, I opened the radiator and squeezed on all of the hoses. I was able to move coolant by doing that. I even loosened the lower hose to see if there was air stuck in the hose. coolant did come out of the lower radiator port and the water pump port when I loosened the clamps at the ports. When driving today the stock gauge was still in the green at about 3/4. Your thoughts? Bad water pump? Thanks for your help in advance.

My Dad taught me about water hoses collapsing from the fluid flow going through them. He kept a bunch of big, open springs and would be sure there was one in every water host when he overhauled an engine.

Wish I had paid more attention; I could have learned so much more that would be like gold, working on a 1980 AMC 304 CJ7 .

 

[hdgapeach]

What Lumpy Grits and DHugg said jarred my memory (gettin' old here). With the engine running at operating temp, if a hose gets sucked flat, you have a restriction in the system. The water pump will pull a vacuum and suck a hose flat. One cool hose and the other hot along with a collapsed hose leans toward a clogged radiator. The stuck closed thermostat could have one cold and one hot hose, more than likely without a collapsed hose since there's minimum (if any) coolant flow.

 

[jdcaples]

When was the last rod-out done on the radiator?
Hint-Don't use 'tap' water on the refill-Distilled water only, with antifreeze.
LG

When pre-dilute antifreeze became common-place, I stopped buying distilled water and 100% Prestone. I never looked back and haven't had "specific gravity-failing" antifreeze since.

Jon