Cold lower radiator hose.

[Jeremy-b]

With engine cold
Take rad cap off and then take the small hose off rad cap opening, the "overflow tank" hose
Blow into the hose, should be easy to blow thru and you should see/hear air bubbling up in Overflow tank
If its hard to blow thru and then gets easier you had a clogged hose or bottom of overflow tank was dirty
If so then clean out the overflow tank and hose, that is why upper rad hose was collapsing

If hose and tank were clear, replace rad cap its recovery valve is broken

Top up radiator, cap still off
Start engine
You might get a small surge of coolant over top of cap opening, then it will drop down and stay down at top of rad no overflowing
Let it idle for 2 minutes, there should be NO overflowing
If you are getting a constant overflowing at rad cap opening you have a blown head gasket or cracked head, period
This is causing the rock hard upper rad hose

With rad cap on, after about 5-8minutes the upper rad hose should be rock hard, 14psi internal pressure from coolant at 180+ degrees expanding
So that's normal

Radiator is there to dissipate EXTRA HEAT, so outside temp and engine heat generated would dictate upper and lower rad hose temps
Normal temp on the dash gauge would be just below the 1/2 way mark, 1/2 is about 205degF on Ford gauges
If yours is at say 1/3 then your thermostat is stuck open or the wrong one, Fords use 1990-195degF thermostats
When driving the temp gauge can go slightly above 1/2 when climbing a hill at speed or pulling a load, thats normal
3/4 on gauge is overheating, pull over and let engine idle at higher RPM to cool it down, if its still going up shut off the engine

I just cleaned the over flow. It was clogged. But I let it run for 10 minutes with the cap off and heat on. It still came over the neck slowly.

 

[RonD]

It WILL come over the top after 2 minutes or so, but not before that
Any liquid expands when heated, thats how pressure cookers work

Engine cold(70degF) the coolant is say 2 gallons volume
When it gets heated up to above 120degF it is now 2.1 gallons, so after 3-4min idle or so, but before that no coolant should flow out of rad cap opening
Except an initial start up adjustment, if you have coolant flowing out before the 2 min time then head gasket issue

When engine/coolant gets up to 190degF its 2.5gallons and this is what causes the 14psi pressure in the cooling system
There is a large valve on rad cap that will release hot coolant so it can flow over to the over flow tank
This happens EVERY TIME engine is run more than 20min
When you shut the engine off the coolant cools down a shrinks in volume, 2.5gal goes back to 2gal, if any coolant was sent over to the overflow tank then a smaller valve on rad cap opens and SUCKS coolant back in from over flow tank
If overflow tank or its hose is clogged then upper rad hose will collapse because it can't SUCK back in coolant

 

[Angie]

just 1 other thing to add, check your coolant velocity. more pure water = lower temp allowances. Not sure if this would affect your issues or not.

cheers

 

[Jeremy-b]

Thank you