R19 Upper and lower radiator hoses are collapsing

Hello, after a lot of searching, I can not find whats wrong whit my R19 Upper and lower radiator hoses are collapsing on throttle, on idle everything is ok. I changed thermostat and washed the cooling system, but no luck. I tried to open expansion tank cap and change the cap itself, but still no luck. There is no overheating, car temperature is stable. I just dont know what to do



My car: R19 1994 1.8 66kw mono injection.



Hope to find help here.