It'* a new master cylinder, but I'll try that. Great advice, thank you.

@carfixer007 I took the master cylinder off, and plugged the ports, I couldn't push the cylinder in at all.

There'* either air in the system or the ABS module is bad.. I remember some older GM'* that had dump valve issues with the unit and this would happen. We used to rebuild them.

@carfixer007 What does that involve, replacing worn o-rings and seals?

They sold kits with the valves, springs and seals. That was a long time ago. Late 80'* and 90'*.

@carfixer007 Is there a way to test the ABS Module?

Not sure what all you can do with this model year but you need a factory capable scan tool to test it.

I have an Autel MP808 that I use to bleed the Anti-Brake system.

If it has the special tests available it should work. Usually when there'* an internal fault it will code.

@carfixer007 I re-bled the brakes again today, then took it out for a drive. The pedal went down a little when I stepped on it, but the car stopped fine and the pedal stayed put. I'm going to go ahead and drive it for a few days and see how it goes. I want to thank you for all of your help, I appreciate you taking the time to respond.

Regards,
Jack