How much expansion is normal for the top radiator hose? My 3L's top radiator hose swells to about 1 1/2 times it's normal size when the car's at operating temperature... the hose also feels sort of sandy underneath... I get the feeling that it's way past it's use by...

If you get the feeling that it's way past it's use by date then change it
they shouldn't swell at all
and they will allways go at the wrong time