Mr HEMIFRED, have you found your problem yet? Mine is doing the same thing as yours. We even pressure bleed them,no air in system no pedal. When we get all the air out it feels like it has a pedal,but when you push it down to the floor it goes. New master cylinder,new hard line to the rear,new calipers(all Wilwood). I just replaced the 2 braided steel brake lines to the calipers,will bleed the system again this afternoon. I have been told the braided lines never go bad,but that is the only things I had not replaced yet. I have never run a residual valve on my dragster before,Wilwood says to have brakes I must have one. My understanding of a residual is if you do not have one the fluid can run back to the master cylinder and let the piston retract back into the calipers and you will have to pump the pedal a time or 2 to get the pedal back up. That's not my problem you can pump the pedal all day and they never hold. They are like yours block off any line and they hold.

Hope you have fixed your problem and can tell me the fix.

P.S. I am sure you check this also,with one of the lines unhooked to the caliper when you push the pedal to the floor how much brake fluid come out? Mine looks like about a teaspoon full comes out.