The turbine has a nacelle that is rotatably mounted on a tower. A yaw system (2) comprises two brake units (B1,B2) for exerting braking torque on a brake disk (16). The brake units are annularly arranged around the brake disk that is attached on an inner bearing ring of a yaw bearing, where the brake units are actuated hydraulically. The brake units comprise brake pads with coefficients of friction that are different from each other, where one of the brake units is pressurized with two different brake pressures. An independent claim is also included for a method for yaw adjustment in a wind turbine.