All of my previous vehicles until this wonder-mobile have had a non-pressurized coolant tank. The radiator hose stays firm under full operating temperature conditions.

Last night, the low coolant light blinked on... I thought not so nice thoughts since I was road testing again to make sure that all the other issues have been resolved...

Anywho, turned around came back, level did not seem too low in the tank, but added some anyway. The radiator hose did not seem firm at all. Seemed very squowshy (sp?). Thought that was odd, until I realized that there is an air bubble at the top of the coolant tank. This bubble doesn't create that hydraulic action that the non-pressurized coolant tank does I thought to myself.

But self wants to confirm this thinking with another good working model.

Sometimes, it is necessary to take the cap off untill T-stat opens and then squeeze the coolant hose to push the air out of the top of the rad and back into the res.

So should it be as firm as the non-pressurized tank system or what?

The hose should remain soft after warm up with the rad cap on.

Low coolant light can come on for no apparent reason. I have seen it two or three times within a short while with sufficient coolant, but the problem never came back yet.