I don't believe there is an actual adjustment to the brake linings themselves as on a car or truck. What you're adjusting is the free travel of the pedal before brake engagement by changing the length for the linkage. That should raise or lower where the pedals rest at full up. I adjust mine separately so they engage at the same pedal height for equal braking each side. I then connect the pedals being that it's an hst with the drive pedal and brakes on the same side making brake steering useless. Mine is a CK30hst and your DK40 may be different.