1996 Dodge Grand Caravan brakes problems

Front brakes failed causing them to catch on fire while driving down a hill, brakes have been replaced but still do not operate properly.

For 3 summers in a row, we have had to recharge the air condition system for it to only work 3-4 weeks at a time. Our mechanic says that it isn't that the air conditing unit has failed it seems to be loosing the freon some where.the locks on the van to the tail gate doesn't seem to work correctly, 90% of the time you have to beat on the lock from the out side for it to unlock. We have also replaced the brake pad approx 3 times and they still squeak and seem to grab at times.