Brake Problem on a 1995 ford????????

[brett1]

I did the brakes on my 1995 Ford F-350 and now my brake pedal slowly bleeds down with the engine running as in a defective master cylinder, but
I changed the master cylinder. It does not bleed-down with the engine off.
The rear brakes have been adjusted, the system bled. What is the cause?

 

[junkyard jim]

The valve between front and rear brakes probably has air trapped in it (if it's the same as older ones) How did you bleed it? Pump the pedal? If you go down more than 1/2 way, you may have ruptured the seals in the master (doesn't sound like it though) Probably needs to be power bled. (or one of your hoses is ballooning up with your foot on the pedal)
Just had another thought. Hanging up caliper can do this as it slooowly engages.