Alrighty, I just had a major scare while driving my 69 on the highway, my brakes went dead to the floor, after asking around with some of the classic car old-heads in my town, they generally agreed that my Master Cylinder is shot.

So here's what I did.

1) Checked fluid level, it was fine.
2) Checked for leaks in lines, none whatsoever.
3) Bled the brakes, no pressure.
4) Bench bled the cylinder, pressure while engine off, not while running.

After doing this, the only change I noticed was that I'm getting pressure with the engine off (I wasn't before), and the pedal still drops to the floor when it's turned on.

So, do I need a new master cylinder, brake booster? Or both?

 

New Master....

 

Sounds like a new master is needed to me.

Also, if you asked the "old timers" for advice and that's what they gave you, you are almost better off listening to them than asking online to people that you don't know what their background is

I've seen more bad info given out on here (and on other online forums), than I have ever seen in my life. Some stuff I can't even believe people come up with.

 

Sounds like an internal leak in the mc. Fluid is passing by the piston instead of being pushed out by it. Normally if it is in the rear, you will see fluid leak down the firewall. If it is the front you will see nothing.