I realized I was backwards with the diameter and I need to go with a smaller diameter master cylinder. the brake system was completely apart and cleaned the wheel cylinders and calipers were rebuilt all of the brake line were cleaned with brake clean and blown out with air so I don’t have a contamination problem. I rebuilt the servo (it was bypassed prior) and about the same time I installed it the master cylinder started going bad and I thought it was the servo so I bought a rebuilt unit on E-Bay and after installing it I had the same problem with the pedal going down so I installed a new master cylinder.
Back to the original problem the brake pedal needs to be pumped up after the car has been sitting it was doing the same thing with the other servo I seems to get better after bleeding the system but comes back after a week. The brake fluid doesn’t go down. like I said I am going to replace the brake lines at the servo this week and blled the brakes again.
Jimk