That's good to hear, and to be completely honest I don't think I've ever seen the brake warning light come on in that car. Maybe it's burned out or bad wiring?
Yep, 4 wheel drum brake systems don't use prop valves. The adjustable in your rear line should do just fine.
Your going to have to figure out which part of your system isn't working for you. Try disconnecting the brake lines at the master, get some brass fittings and block the ports at the master. Pump your brake pedal and see if it holds. If it does, hook up the front brake line and bleed the system and then see if it holds. If it doesn't, you need to check the front system out. If it does, well, I would hook up the rear and try to bleed that out. If it doesn't hold, then you know for sure where your problem lies. If it does hold, I would guess you had some real pesky air hiding in there.
