95 Trans AM

Hi I have a 95 T/A that on occasion does not want to come out of park. It is just like not pressing the brake and trying to get it out of park. (Yes the brake pedal is being pressed sometimes with both feet) Even if the car is not started it will not come out of gear. You can sit and fight it for a long time then get fed up go in the house for 5-10 minutes and come out and try it again and it works fine. Like I said it only happens on occasion. I figure it has something to do with the brake having to be pressed. Only I do not know what part this effects or how to fix it. Any help would be greatly appreciated.