Thanks Tom for that answer

Today I will try to check some things.

About gravity, just after HX, on HX R14 liquid line is 15cm pipe placed horizontaly, to it there is brazed captube going to evap. So I don`t see any chance for liquid refrigerant, that it`s "staying" somewhere in pipe or something :|

Only subcooling on stage III is captube wrapped around suction line. Static pressure @ 3 stage is 10bar.

I thinked about adding some more captube to 3 stage.