I can tell you that by law, the parking brake is required to hold the vehicle in all forward and reverse gears when fully applied. Other than lurching, it should remain stationary. I know when I got mine, I was not pushing down far enough as I was afraid I was pushing too hard. My last car had the same style of parking brake but you really had to push with a lot of might. You might have your dealer check that out, too, since you are pushing down all the way and the vehicle is still moving. It may be just a simple adjustment.
