well my 86 brake locked up completely(cant even move it) and i pumped the brake till it gave way and let it roll again. but now my brake goes all the way down and i have full brake fluid. so what happened. i am thinking my brake master cylinder is out. and thanks for any help.

 

I think I would start by taking each wheel off and inspecting each brake caliper. Are any of the calipers leaking, do the caliper pistons move ok? If things are ok at the wheels then I guess I would remove the master cyl and see what is going on with it.

You can also just try bleeding and see what happens. If you open a bleeder screw and pump the brake, does the it master cyl pull fluid out of the reservior, that is does the level go down? If not, I would suspect a master cyl problem.