Ok here is the situation, Brake pedal has firmness until I start the Jeep up then it goes to the floor. Here is what lead up to this problem.

95 YJ, 9" disc brake rear, (been in for a few months now) and just replaced the D30 with a D44 RC, High steer...yada yada yada. Here is the problem, first and hate to admit it had the calipers on the wrong sides (on the front of course), the bleader needs to point up not down. Bled the brakes again and with motor off the pedal was still a little mushy, with moter on to the floor. note: I had taken the o-ring out of the proportioning valve when I put the 9" in, brakes worked great. So decided that maybe that was the problem, so put it back in. Bled the fronts and got a firm peddle until the motor was started....to the floor again. So I just sent my wife to the auotparts store again to get more brake fluid (she was real thrilled) and I am going to bleed the hell out of them (from farthest point away to the shortest for those of you who wanted to ask if I was at least doing that right) But am I missing something. Has anyone else had problem after this swap?

Thanks in advance for any help in this situation.

BlueYJ

Mine does the exact same thing. I think the master cylinder just doesn't push enough fluid to the rears and front. The stockers were designed for smaller pistoned calipers and drum cylinders in the rear. You can tell by the resevoir size too. Do a search on the Corvette master cylinder swap. They are made for large calipers and 4 wheel disc brakes. When I find time and money I am going to do this.