On my 2000 Caravan when you apply the parking brake it will start to hold if you push real easy on the pedal. But in order to get to hold with sufficent pressure you have to push down a little harder. When I try to apply more pressure the pedal slips free and goes all the way down and the brake does not hold at all. You can push about two to three clicks and then it slips free and goes to the floor.Any ideas ?