Originally Posted by luckynumberslevin
So im loosing my mind on what my problem may be!
I upgraded my brakes on my truck, (62 gmc) from the drum/drum set up to a power disk/drum set up. I used a 79 chevy front clip with brand new brakes, CPP master cylinder, prop valve and a 82 drum set up in the back.. I ran all new lines and new cylinders and calipers. After sealing all my leaks, and bleeing the front and the back for hours i can still easily put my foot to the floor with the brake pedal. I have adjusted the rear shoes tight to the drum and still right to the floor with some amount of resistance. So aside from bleeing and bleeding what am i forgetting or missing?
You bench bled the MC? MC not lower than the calipers?
There's a chance the MC sat around long enough for the seals to have hardened. This causes the fluid to internally bypass. Sometimes, exposing them to brake fluid for a period of time will bring them around. Sometimes not. Could be damage to one of the seals when the MC was assembled.
Other things could be a way out of spec pedal ratio, a severe mismatch of MC bore to the wheel bores.