Help!!! Bleeding brakes

[lucifer]

Need some help and this forum is the place to get it.

I have installed 4 wheel disc on my 64 with new master cylinder and proper proportioning valve from CPP. I have properly bench bled the master and gravity bled the calipers,,,then power bled the calipers...then did it all again and I can't seem to get any pedal. Brake rod is correct and so in the master to booster rod. Proper stroke with about 1/4 inch clearance on the pedal to booster. All components are new and properly matched. I can get a partial pedal with three pumps and it will hold. Just can't get a hard pedal!
This should be so simple and I have done it more times than I care to admit.
WHAT AM I MISSING?????????????

Luc

[rustbucket66]

I had something similar with the Willwood 4 piston calipers in my other car. Tried everything. What I found was air trapped in the calipers on the side the hose is on. I took the thing off with the bleed open slightly, and kind of held it upside down in my hand. Imagine the air inside that side of the caliper, so hold it so the bubbles can rise, and then tip it to go into the bleeder side of the caliper. I know this sounds bizzarre, but air can get trapped in the inside half of the caliper. Try it.

[Deryl]

Don't know if it will work, but..... a good friend who is an ASE certified master mechanic told me that he has not bled brakes by pumping in over ten years. When he gets a car in for service he cracks the bleeders on all four wheels (on a lift of course) and lets the gravity bleed while he does the remainder of the service. He makes sure the master cylinder does not get too low, but he knows his time schelule on services so that is not a problem. The last two brake conversions I have done, my 63 C10 an a 280Z I did this way and they worked perfect. No fuss, no muss. The Z, I worked with for hours before I called him. Tried his method and viola, they were done. I never pump brakes anymore!

[rustbucket66]

The gravity bleed thing works well. I kind of assumed you did that. Keep in mind what I said previous if it doesn't work. You definately have air in the system somewhere. The factory calipers just have the one piston and is easy to bleed. The multi piston calipers take the fluid in in one side, then have a passage over to the other side that has the bleed screw at the top. Air can get trapped sometimes on the side that the line comes into.

[dicer]

You can also get a cheapy harbor freight air powered vaccum pump, and use one of those little brake bleed resevours and vaccum the system, works good.