Strange in that it did not do it last fall before the long, cold winter stored in a garage. Went for first drive and pulled left (left front brake working, it turned the wheel, right front not as much or not working). After driving a few miles and braking repeatedly, right front worked again. 2 days later, did the same, but corrected itself after a shorter drive. After a week or so, corrected itself after 3-4 braking. Question is whether it is master cylinder or just air in the lines. I have new calipers and hoses on the car from last year and new fluid.