Hi Steve. Be sure to clean all around the bleeder  to get as clean as
possible. then take a drill bit that will fit inside the bleeder and twist by  hand
between thumb and fore finger, BY HAND,  inside of the bleeder. You  will be
supprised of the crap that will come out. drible your choice of rust  penatrant
inside and around the bleeder. do this several times and let sit over  night.
If you are feeling brave use a torch to warm it up or a heat gun. and  repeat
cleaning out the inside of the bleeder with a drill bit.

It seem that the little rubber cup that protects the end of the bleeder and
help keeps stuff out
always seem to disappear ergo crud inside of the bleeder so not only is it
rusted from the outside but also inside.

My guru showed me this trick years ago and I have not snaped one off since
doing this and taking my time.

Jim Morgan 86 Gl "breadbox"