Since I purchased my ‘12 JK in May of last year I have only put it in 4H twice and both times I have immediately lost the pressure or resistance in my break pedal. I have to press it almost all the way to the floor to get the vehicle to stop. The first time this happened it slowly recovered over the next 24 hours. This most recent time it did not recover for 2 days so I took it in to the dealership, they seem puzzled by what is causing this or why it would be related to the 4x4 system. Has anyone else had this problem?