Roy,

Actually, on older cars, the metal spring was in the lower radiator hose to keep the hose from collapsing while the engine was running.

With the upper hose collapsing when cold is a demonstration of thermo dynamics and the pressure inside the cooling system being less than atmospheric pressure.

This can happen if coolant level is low, as air is now in the system. Cold air contracts, warm air expands.

Opening the coolant fill cap will draw in air and equalize the pressure. It also means that your system is not venting properly, or you are low on coolant.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D