The parking brake lever will not be stiff, it will go to the top if you use your arm power and the parking brake will not be good enough to stop the car. I have inspect the rear brake pads och brake discs. They are good enough. I have inspect the brake cables, they are ok and I have adjust the cables so it go all the way back to the stop-pins. I have press`d down the brake pedal 20-30 times hard so it will adjust the pads. What is more to do? Is the problem the brake calipers? Could the adjust mechanism be bad?