I just posted this same question about a week ago due to I had the same issue. I was told about the lock washer idea as well.
I found a standard washer from my hardware stash and cut one side of it so I could get it over the handle rod. Once I got it over I bent it back and now the brake release handle works as before.
Its a simple fix that works.
Last edited by loco340cuda; 05/02/1612:09 AM.
70 Cuda 340 4 speed - now stroked to 416ci (SOLD) 2017 Mustang Shelby GT350