I have been playing around with the '94 after picking it up last week and noticed the Upper radiator hose colapses when the car has cooled down after a drive. I thought it was just a weak hose and replaced it, but it still colapses.

Any ideas on what would cause this?

 

your overflow isn't sucking coolant back in when the car cools off. try a new rad cap.

 

Also make sure the cap on the overflow is installed correctly. If you have played with the hoses on the cap and reversed them the unit doesn't vent properly. Make sure the tab of the cap is facing to the rear and the hose from the radiator feeds from the right.

 

basically your cooling system stays pressurized, the above to are possibilities, but you should also make sure your overflow tank tube is not clogged, just do a simple blow test on it

 

Replacement cap fixed it. I love simple solutions.

 

they're just about as nice as cheap solutions.