Hi all,

I have been having brake problems recently with my 56 3100. The brakes are all stock except for a dual master cylinder & adapter from American Classic. All 4 drums were turned and new shoes installed about 500 miles ago and I put new lines on when I restored it 4 years ago. No power boost.

The brakes seem weak when I start pushing them and then when the pickup has almost come to a stop the pedal drops a little and the brakes grab hard. It feels like maybe I am getting only the front or rear brakes most of the time. Could it be air in the lines? Overfilled master cylinder? Something else? Any troubleshooting advice would be welcome!