This is on a front disc/rear drum power brakes car (71 Charger R/T):

1) I have been battling a brake problem. One thing I have observed is that the braking deteriorates pretty badly after a couple of hard stops. Is this just normal brake "fade"? How much braking should it take before fading begins? How fast should "normal" brake operation return?

2) I bled my brakes for about the fourth time today. Unbelievably (to me), a large amount of air came out of the left rear line. Even though it doesn't leak fluid, is it possible that somewhere in the system air is getting in when I release the brakes?

Thanks for the help guys.

Greg

If you're losing pedal you're sucking air in some where. I had the same problem with my 71 Satellite. Turns out to bleeder valves were letting a little air in. After a fresh bleed they were great but would start going away after some heavy braking. I still haven't replaced them but I'm sure that will help since I get air bubbles from the rear also.
Even with a stock front disc set up if you hammer the brakes a lot they will fade some but air in the line is a different problem.
To tune mine I have a manual prop valve in the rear line and I got rid of the factory block. My front and rear brakes are completely seperate. After playing with the valve and getting it just right it's the next best thing to ABS!

that is pretty much normal drum brake fade & cheaper linings contribute to that & a problem issue with bleeding is having the bleeder screws not closed enough when your helper releases the brake pedal & air gets sucked back in past the threads & being sure the MC is bled(on or off the car) 1st.

Thanks guys. I think I am getting air sucked back into the system, possibly at the bleeder.