Raidiator hoses collapsing no flow from hoses it seems 91 chevy vandura 3/4 ton van v6 when I turn on heater blows hot air but then hoses really collapes, I changed the thermostat added water is this normal, or maybe heater control valve? I dont have a temp gauge and doesn seem to be over heating whats up
Possibly your overflow bottle is not working right. Plugged up somehere? Water expands into bottle and then draws back into radiator. If it cant draw back it will collapse hoses from suction. And make sure your system is full and your radiator cap is good. You might try a new cap first. And your upper radiator hose should have an internal wire spring that keeps it from collapsing.