Coolant pressure... can I ask for a few guinea pigs?

I am wondering if the engine is pressurising the water jacket.

I feel the need for an experiment... well what do you expect from a chemist?

The top hose is getting quite hard after only a mile of driving, perhaps not even that. So far no water has been forced into the expansion tank. I have done a couple of 3 mile journeys and nothing out of the ordinary happened. I can squeeze the hose between my fingers about a quarter inch each side. I want to know if this is normal.

This is where you can become an experimenter. Can I ask you good people on this forum if you would drive a short distance from the engine being cold with the passenger seat up and give the hose a good squeeze and let me know how squigy it is? As I say I can squeeze mine a quarter inch after a short distance.

If anyone can do this and report here that would be great. Thanks

if the radiator is full when cold and coolant leve is ok in the bottle everything is ok., No need to squeeze.