1994 Civic DX 5-speed, Non-ABS. I replaced pads and rotors along with bleeding front brakes. Pedal is firm but fades when braking or sitting at a light... pedal start to fade to the floor with light foot pressure. OK, I figured the cups in the master cylinder were letting fluid past, hence the fade. My Civic has 122K miles on it and I am not the first owner. Replaced the master cylinder. The old one had good suction to the power booster. Bench bled the new master cylinder and installed it. Bled the brakes... back right first and so on. Pedal feels distent. Start the motor and push on the brakes and the engine RPM goes up whenever you push the brake pedal down... Any ideas? Thanks, Joe

 

check all vacuum lines