Air in Master Cylinder?

[mach1000]

New (not rebuilt) master cylinder. When I drive the car my foot goes about a 1/4 way before brakes actually grab. If I drive it and the brakes "warm up" the pedal gets stiffer. I've bleed the lines several times and don't get any air. Do I have air in the master cylinder? I did bench bleed it but maybe not enough.. Any thoughts?

 

[VegasFastback]

The shaft that pushes the piston in the master cylinder may need to be adjusted. pull the cylinder off the firewall, or brake booster if it's power brakes, and check the rod. It should have threads on it that allow you to adjust the length.