356 K, what is the mass of the metal?
I can't believe that people still use their front brakes. I know that all of your stopping power comes from the front, I just don't use the front brake unless I am burning a few hundred miles off my back tire. Then again, I learned to ride on a 68 Trumpet and the front brake on it worked just like drum brakes on bikes are supposed to.it didn't
Its time to get new brake pads immediately, before it scratches the disc too deep and you have to get a new on one those too. Your back brake is doing all the work now. You need to get it fixed yesterday.
New pads (organic pads if you can still use that rotor) and have mechanic mic the rotor, sounds like you might need that replaced too. Outside chance it could be brake dust or debris, How much pad is left? If you visually can't see much, replace immidately.
