i recently have started to have a problem with my brakes. they are squishy. when you push the pedal, it goes all the way down, fairly easy. i really have to push on them to slow down from higher speeds. it almost like the pressure isnt staying. some say the master cylender, some say its the brake lines. one caliper isnt closing hard enough. its greased and moves freely. there are no fluid leaks and no air bubbles in the system. now i get these brakes hot 3 or 4 tines a week and when i say hot, you can see the pic i attached. any suggestions where i start first? im getting new rotors and pads soon but i dont think its going to solve my problem.