> When I take my beetle for a ride the brakes the work normally with no noise, but after driving for about 10 km I begin to ear a gride noise when I brake, each time the wheel makes one turn on the rear right wheel.
> The drum was removed and found nothing and the noise disappeared for a while. Now it is back again and the noise is higher and begins sooner as the time goes by.


Check that the wheel cylinder retaining bolt is correctly tightened. I
had this same problem on my 74 super several years ago.

Chris