Return radiator hose collapse

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sgtjd

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I have a 351C and it seems the return radiator hose collapses. Radiator is full no leaks. Heat works. There is plenty of pressure when I release the radiator cap and the hose returns to normal. Not sure if this is normal or what.
 
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Although apparently not intended for this purpose, but you can buy a spring like coil to insert into the lower hose and that will prevent the collapse. However, a new cap first might be the simpler fix. I have heard that as well.
 
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Also check the overflow tube, to make sure it isn't plugged. When the engine warms up the coolant expands, compressing the air in the system. When the air pressure exceeds the rated pressure of the cap it vents to the atmosphere. As the engine cools the coolant contracts, causing a vacuum in the system. If the cap or overflow tube don't function properly the hoses collapse.
 
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I have a 351C and it seems the return radiator hose collapses. Radiator is full no leaks. Heat works. There is plenty of pressure when I release the radiator cap and the hose returns to normal. Not sure if this is normal or what.
I have a 351C and it seems the return radiator hose collapses. Radiator is full no leaks. Heat works. There is plenty of pressure when I release the radiator cap and the hose returns to normal. Not sure if this is normal or what.
The return hose is the upper and that collapses and you have flow to and from the heater core?
I have never heard of that but having a inner spring in the suction hose is a must have IMO. 🤷🏻‍♂️
 
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The return hose is the upper and that collapses and you have flow to and from the heater core?
I have never heard of that but having a inner spring in the suction hose is a must have IMO. 🤷🏻‍♂️
Okay, to be clear here, I have always thought of the 'return hose' as being the lower hose 'returning the water back to the engine'. The upper hose being the 'rad hose'.
However I could be wrong, as I am many times. I learn something new every day.
 

piper62j

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The lower hose is the suction hose which takes the low temperature coolant from the radiator into the water pump, sends it throughout the engine,, after heating and out thru the thermostat housing, into the upper hose, back to the radiator to be cooled.. The lower hose did come equipped with a stainless coil spring inside from the factory to prevent collapsing. I'm not sure if the springs are still available, but you may be able to obtain a lower hose that is reinforced to prevent collapse..
 
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The lower hose is the suction hose which takes the low temperature coolant from the radiator into the water pump, sends it throughout the engine,, after heating and out thru the thermostat housing, into the upper hose, back to the radiator to be cooled.. The lower hose did come equipped with a stainless coil spring inside from the factory to prevent collapsing. I'm not sure if the springs are still available, but you may be able to obtain a lower hose that is reinforced to prevent collapse..
NPD list them in my 'old' catalog. #8A286 for about 6 bucks today.
 
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Here is what I run and with the wire hose clamps.
 

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Joined
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1972 Mustang convertible, 351C 2V with FMX (#'s matching)
Currently equipped with 351C 4V 4BM, .060 over, roller cam, Sanderson block huggers, -AC
Sarge.. (I was 11C back in the day when the first sand war kicked off)
I hope we helped you ID your situation and you are sure of which hose is collapsing on you.
The winds died down here so i had to take her out again tonite and took a few pics of the hoses and again the lower is suction and has a SS spring in it to prevent collapse which will be devastating to a clev if coolant flow is stopped.
Anywho, hope we are helping! 🇺🇸
 

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Lower radiator hose is the suction/return of cooler coolant going back into the engine coolant jackets to absorb more heat to shed via the radiator cooling fines. I have always seen a large SS coil inside the lower radiator hoses to prevent collapsing on high suction when the water pump is pulling for ever more coolant which causes aa cooling system vacuum, or when the coolant cools off and the fluid contracts, and the the vacuum relief valve in the radiator cap is not working. In either case the lower radiator hose's SS spring prevents it from collapsing.
 
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Upper hose. I ordered a new cap to see if that works.
Now I'm totally confused. Is it the 'upper', t/stat to rad hose, or the 'lower' rad to water pump hose that is collapsing?
Here's what I might suggest. Replace both upper an lower hoses. Add the springy thingy to the lower if it is not supplied with it, change the rad cap, I think it is a 16lb cap and I may also change the T/stat for a Cleveland specific 192 degree. If you are not aware, these have a "hat" on them that seals off the restrictor plate. I don't have the part number at hand, so if needed, someone will have them and post for you.
It could be that your hoses are getting old and time to replace anyway.
 
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1972 Mustang convertible, 351C 2V with FMX (#'s matching)
Currently equipped with 351C 4V 4BM, .060 over, roller cam, Sanderson block huggers, -AC
Upper hose. I ordered a new cap to see if that works.
Yes, then you definitely have air getting into the system. The old style caps weren't equipped to release the pressure very well at approx 15psi so hopefully your new cap will, and another thing to check is ensuring your upper hose isn't blistered under the clamps and old and frail. Probably a good time to change it out if its old and soft. Keep us posted!
Upper hose. I ordered a new cap to see if that works.
 
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I see some mentions of maybe air being trapped in the cooling system. Could be. I have seen some YouTube videos showing how to burp an engine, to get rid of trapped air. Lynda and I did one also, as many of the YouTube videos I saw were not giving what I felt was accurate info. Here is ours:



I hope someone finds that info useful
 
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sgtjd

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I have a 351C and it seems the return radiator hose collapses. Radiator is full no leaks. Heat works. There is plenty of pressure when I release the radiator cap and the hose returns to normal. Not sure if this is normal or what.
Figured this out....replaced the radiator cap and the overflow radiator hose that was clogged. Once done everything returned to normal. Thanks everyone ☺️
 
Joined
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Messages
275
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176
Location
Wisconsin
My Car
1972 Mustang convertible, 351C 2V with FMX (#'s matching)
Currently equipped with 351C 4V 4BM, .060 over, roller cam, Sanderson block huggers, -AC
Figured this out....replaced the radiator cap and the overflow radiator hose that was clogged. Once done everything returned to normal. Thanks everyone ☺️
Breathing is a good thing!! Glad to hear you are all squared away. 🤙🏻
 
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