Hi Casmihok,
Here is the description of this system so you can understand a little more what it is doing.
As for it moving on a hill, it depends on how steep the hill was. If it was a pretty good incline then this may be normal because the parking brake shoes just can't hold the weight of the vehicle on steep hills. In those cases, it is just there to help the parking paw hold the vehicle. However, this is rare and it should hold the vehicle on most hills.
Here is the procedure on how to adjust the brakes. Most likely they just need an adjustment. Worst case scenario they need to be replaced.
Let me know if you have questions and I will be happy assist. Thanks
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Monday, July 8th, 2019 AT 12:19 PM