Chumley

I replaced my master cylinder, so when I went to bleed the brakes I noticed that the little button on the proportioning valve seemed to be stuck in the depressed position(which I know it is supposed to be while bleeding) Fluid flowed freely while bleeding, but is there a way to get this button unstuck? I'm concerned that my brakes won't work correctly when I'm all done. There was no abnormal braking symptoms before the old M/C died. Any advice?
Chumley