Upper radiator hose collapsing

My neighbor has and older Olds Silhouette.

A couple of days ago he came home and there was steam coming from under the hood. He had replaced a cracked t near where the heater hose meets the firewall.



FF 3 days, In being a friendly neighbor I was looking at it with him. There was no pressure in the system so I pulled the radiator cap, sludge city, including a 3/4" strand hanging off the radiator cap.

Cleaned the cap and neck, refilled the radiator with the engine running, and told him to let it keep running to pressurize the system to find the leak. As it is warming up to temp I notice the upper radiator hose collapsing, and he felt compelled to turn off the car before enough pressure built up to find the leak.



My prognosis was the upper hose was collapsing because the radiator was clogged, but maybe a new stiffer hose would help, flush the system, refill with a universal coolant and repair the coolant system leak.



Is it a Dexcool clogged radiator?

Is the radiator toast or can it be flushed.

What other conditions besides weak upper radiator hose or clogged radiator collapsing of the hose.



thanks.

I forgot he reports car temp gauge has remained in the normal operating range, no overheating

The upper hose collapsing indicates that the thermostat is closed and the water pump is doing a great job while the engine is still cool enough that there is no pressure in the system. Check the transmission fluid for coolant contamination first. If the ATF is good check the engine oil. If that is good drain the cooling system and refill it with water and Cascade and run the engine till fully heated, let it cool, then flush with fresh water and watch for new contamination. If the engine has an oil cooler that could be the problem.

Cascade like in dish soap? Many thanks for the thermostat suggestion. I will look at the other advice also!