My brakes work great..no noise no problems..until it gets hot!!..when the temperature exceeds 75 degrees outside and my driving is extensive the steering wheel shakes and I get lots of vibration when I apply the brakes..it almost feels like the rear calipers are not disengaging fully..I have replaced all rotors and pads and still have the same problem..the fluid level in the master cylinder is just below the full line,so its getting room for air relief..the only thing I can try now is drilled and slotted rotors or new rear calipers..any suggestions?..its getting expensive..