Brake problems need advice.

[bgbmxer]

88 dodge shadow that has had all brake lines front calipers rear Wheel cylinders all new hoses new booster and a jy mc. I have a rock hard pedal when the car is off. When I fire the car up it gets a little spongy but not to the floor. I did do new vac lines but I have 15 lbs of vac at idle and have it hooked up to the intake and the line that goes to the interior for the heater controls. Could my new booster be bad or should I try something else?

[black86glhs]

If you had a hard pedal while engine running, then I would say yes to the booster. In your case, I'm thinking no. I bet the MC is bad or you have air in it. Did you bench bleed the MC or at least bleed it on the car before you redid the rest of the brakes? If no on bleeding the MC first, I bet it is bad or has air in it. If you did bleed the MC, then it is bad.

[bgbmxer]

I'm thinking the system just has some air in it yet. I did bleed the mc first but with all new lines and components everywhere its prolly just air. It doesn't go the whole way to the floor just spongy

[shackwrrr]

When bleeding it don't pump the pedal. Just open the bleeder, push the pedal down, close the bleeder, and release. Pumping it breaks the bubbles up and makes it damn near impossible to bleed the system out.

Also sometimes pushing the calipers in will push any air out of the mc into the reservoir.