Hey guys, great site!!
I have CNC pedals and dual cutting brakes. I have bleed them countless times. A first i had a little brakeing power, just enuph to lock the tires. the more i rode the worst they got. it seems that all the air came together and is stuck in one place.
Here is the weird thing... If i push the foot brake to the floor and HOLD IT there and pull both cutters at the same time they are rock solid. WHILE STILL HOLDING THE CUTTERS tight i let loose the foot brake and when i push it again it too is rock solid. when done in this combination you could not ask for better brakes. as soon as i let loose and try either foot of cutters i have absolutley nothing! it seems to me that you have to first push the pedal to fill the cylinders on the cutters in order to get pressure there then while holding pressure there you then can build pressure at your pedal. when you have the pressure on both sets of brakes they are not spongie at all. So do i have air or is there something else going on? I am out of ideas any help would be great!!!!
PS I just made a Power Bleeder, but have not yet used it.

Air for sure. Try the power bleeder, make sure to squeeze calipers all the way in and elevate bleeders, then see what you got. The more you ride it and bleed them right after , the better they get usually.

pull the cutter handles all the way down hold them there and bleed brakes had the same prob air in the cutters

Pull them down? Only if they are mounted in front of driver where you pull on them to make them work. If they are mounted between the seats, pull them all the way up and release a few times while running the power bleeder. If you try to force the plungers in the wrong direction, you'd be screwin up big time.

Mounted by the steering wheel, so pull down...10-4. So if there is air, how come they don't feel spongie when you start to let off? like i said they feel rock solid, once you push foot pelal-hold then levers are
solid-hold then relase foot and press again then both foot and levers are firm. Is the air just compressing? If this is the case i still think that they would feel spongie as you are releasing.

What type of brake calipers are you running and on what size tire? I was having a similar problem and I thought it was air but it turned out to be the caliper was just too small. I changed to 4 piston calipers and everything is great.

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I backed up a steep hill (i only have rear disc brakes) and used the power bleeder and still have nothing. but i did find that if you shut the bleeders on the calipers and pressurize the system useing the power bleeder i have GREAT brakes (floor and cutters). Also found that when looking into the resivour when you push the foot brake and hold then pull the cutters and hold then let off the foot brake the level in the resivour lowers like it is takeing another "gulp." When i let the pressure off the system the level signifigantly raises in the resivour. I am wondering if the seals are bad in my master cylinder. It seems like it is letting the fluid that is between the floor and cutters come back past the master cylinder back into the resivour. Another thing i thought of is that the floor is a 5/8 master and the cutters are 3/4 could this have anything to do with it? Do people typically run this combination or should you run 5/8 with 5/8 and 3/4 with 3/4? just wondering.

5/8 master is too small for disk brakes and will not move enough fluid to make the brakes work well. Replace with a minimum of a 3/4" bore.

FYI When you hold the Brake pedal down the Cutters will always feel rock hard because you are applying master cylinder pressure against the cutter cylinders. Even with a good operational brake system.

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Water cooled Dry Sumped Subaru Powered Turbo Charged Fuel Injected 2500CC Tank. Oh Rah! He who dies with the most Toys not only wins, He also wears them out!

YOU HAVE A STUCK CALIPER.

Interesting ideal, however if a caliper was stuck I would think it would merly fill up with fluid and remain full after all the power bleeding.

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Water cooled Dry Sumped Subaru Powered Turbo Charged Fuel Injected 2500CC Tank. Oh Rah! He who dies with the most Toys not only wins, He also wears them out!

When you go this you are setting the parking brake. Once you push on the brake pedal again it release the brakes. I use that trick when ever I leave my buggy running and get out to check on something.

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