Can't lock rear wheel up on adjuster.

[Rob Needs]

I thought i would give the brakes a once over today,I did it by the book and made the brake board.
But I can't get the rear passenger side to lock up when I have the board on the third notch, its tight but not locked. I can't lock the wheel up on the brake adjuster even without using the brake board.

The brakes aren't that old.