Hitachi ex17-2 swing brake

View attachment 179370 View attachment 179371 View attachment 179372 View attachment 179373 I have a problem with my swing brake or -motor. It can swing the house clockwise but only veeery slowly counterclockwise. I am able to push the boom manually clockwise but counterclockwise the swing brake works as it should.

What is wrong?

Hitachi ex17-2 swing brake