my 64 tbird left rear brake light not working why?

Since the brake light is all that doesn't work, it is wired in parallel to the right brake light. I would just run a new wire from right to left. Save you a lot of trouble shooting. Also, you might want to check the grounds.

can I get the rear brakes to bleed right 92 Thunderbird

92 Thunderbird can't get rear brake bleed what's the problem

You bleed ALL 4 wheels. Start with the furthest wheel from the Master Cyl and work your way to closest. Be sure there is no more air bubles before you tighten the bleeder valve befoe you go to the next one. It could be that the rear wheel cyl might be leaking if you cant get them to bleed out and stay. Appreciat it if you would mark this helpful if it is. Thanks