im in need of some advice or answers. I recently changed out the radiator in my 1988 f150. After installing the new radiator and filling it with coolant, i ran it to check the coolant flow. after driving it for a short time, i checked to make sure there were no leaks and found that both my upper and lower radiator hoses were collapsed. After allowing the engine to cool, i removed the radiator cap and the hoses returned to normal.......any answers????

 

possibly air in the system causing a vacuum situation.

Why did you change the radiator?

No signs of a water pump issue?

 

You need a new radiator cap. That's all

 

Sorry to double post but the cooling system will pull a vacuum that will pull coolant out of the overflow bottle. If the cap is bad it won't let it sucking the hoses flat. Even if its a new cap its junk

 

Replace the cap and the thermostat on general principle.

 

try the cap, i've actually never seen it happen before.

 

Some hoses have a spring wound inside to prevent colapse. In some cases you take the spring from the old one and instal in the new hose before use.

 

Tstat is not the issue

 

Not the issue, but a darn good idea to replace when you have the cooling system open anyway.

 

Thanks all for the advice, i changed radiator caps and presto!!!! No more issue. Thanks for all the help