57 Dodge brake disaster

[MoparMike]

I have upgraded the brake system for this car, 66 Chrysler rear end, scarebird disc brake conversion. All new brake lines, new splitter block. The pedal is spongy at best and will go to the floor if pushed hard enough. I have used both a 68 Fury master cylinder, scarebird recommended for the conversation and a master cylinder for a 77 Cordoba. Both were brand new. There is no power booster currently on the car. There are no leaks anywhere, yet the pedal never gets to the point where I would have any confidence in stopping the car. I realize I Frankensteined this system together, but if there are no leaks shouldn't the pedal get firm? I am at a loss for ideas. Any help would be greatly appreciated.

 

[mrs49]

I have upgraded the brake system for this car, 66 Chrysler rear end, scarebird disc brake conversion. All new brake lines, new splitter block. The pedal is spongy at best and will go to the floor if pushed hard enough. I have used both a 68 Fury master cylinder, scarebird recommended for the conversation and a master cylinder for a 77 Cordoba. Both were brand new. There is no power booster currently on the car. There are no leaks anywhere, yet the pedal never gets to the point where I would have any confidence in stopping the car. I realize I Frankensteined this system together, but if there are no leaks shouldn't the pedal get firm? I am at a loss for ideas. Any help would be greatly appreciated.

Bleed,bleed,bleed.

 

[3175375]

I have upgraded the brake system for this car, 66 Chrysler rear end, scarebird disc brake conversion. All new brake lines, new splitter block. The pedal is spongy at best and will go to the floor if pushed hard enough. I have used both a 68 Fury master cylinder, scarebird recommended for the conversation and a master cylinder for a 77 Cordoba. Both were brand new. There is no power booster currently on the car. There are no leaks anywhere, yet the pedal never gets to the point where I would have any confidence in stopping the car. I realize I Frankensteined this system together, but if there are no leaks shouldn't the pedal get firm? I am at a loss for ideas. Any help would be greatly appreciated.

Did you bench bleed the master cylinders before installing them (either one)?

 

[MoparMike]

Did you bench bleed the master cylinders before installing them (either one)?

Both master cylinders were bench bled before installing them on the car. Yesterday, with the 68 Fury master cylinder installed the brakes were bled and rebled until an entire quart of brake fluid had been put into the master cylinder. At no point was the master cylinder run dry. There was nothing but fluid coming out of all the the bleeders.

 

[Davea Lux]

I would start by checking all of the brake system fittings. Brake fittings can suck air if they are not tight and properly seated. If you have a spongy pedal, that usually means air is getting into the system.

Dave