All, need some help. I've noticed that as i sit at stop lights the brake pedal slowly depresses then catches again, or i have to pump the brakes. I've had the Master Cyclinder replace hoping to fix it. Ford and another shop haven't been able to identify the problem. Was hoping some here could lend some advice. Thanks

 

are you losing brake fluid?

 

Brake Fluid Checked out. Matter of fact I had them flush the system after this started thinking that might fix it. Supposedly the Brake Booster was ok also. The brakes are fine while driving, I don't feel any softness. Its just when i'm sitting still, after a short time period the brake will start slipping to the floor then catch it self or i will let off the brake and step on it again.