Symptoms of having the wrong sized Master Cylinder?

[RidiCat69]

Originally Posted by Oleyellar

....proportioning valve setting, or is there one? Do you have one with a switch that could have shifted? ...

This is very real. If the prop valve/combination valve has a safety switch and you bleed the system with no pressure on one side, that side can close off. The combination block thinks there's a leak and is trying to save one of the circuits. If you do have one like this, the plug in the middle of the valve can be removed and you can visually inspect to see if its tripped. A tool is actually sold to hold this pin in place while bleeding an empty system.

You said you had good pressure when you put the gauges on the calipers. Remember what that pressure was? Was it equal on front and rear?

What is the pedal ratio? If you're coming from a manual drum or a power disc the input pressure wouldn't need to be as high as the manual disc requires.

Here's my favorite one that I've see converting from a manual drum car to manual disc. Firewall deflection. It doesn't matter how hard you push on the pedal if the firewall is absorbing all the pressure.

Binding push rod into the master can be something to look for too, or how about the bushing between the pedal lug and the pushrod, or the bushings for the pedal itself?