JeepWoman

Brakes were fine before old factory booster went out. So upgraded to 95 ZJ booster and master cyl. Have pressure bled the system twice, and pedal still goes almost to the floor. No leaks and got good flow on all 4 when bleeders were opened. Did the exact same swap on my old 93 and no issues. This my 94,did I forget something? All new lines from front to back. Rear brakes were done in the spring.

bad_idea

Where did you source the booster and master? Parts store rebuilt unit? Junkyard unit? The quality of parts from the auto parts stores has taken a dive in the last 5-10 years. You may have gotten a bad master cylinder.

That 94 doesn't have an ABS system on it, does it? I know the early ABS systems were riddled with issues and best just to delete them.

Older brake setups are simple - master pushes fluid to wheel cylinders / calipers. If you have no air in lines or leaks, then the master is ****. Did you bench bleed the master, that can cause you issues with air trapped in it that will not come out at wheels cylinders / calipers.

JeepWoman

Both units came from same supplier from when I did my old 93. Both are new. The only physical difference is the pedal arm. The XJ hasd the dog leg, and the ZJ is a straight shot, so the pedal arm pushes at a angle. No ABS and didn't bench bleed it. Since buying my Motive products pressure bleeder I haven't bench bled anything since.

bad_idea

By 'new' do you mean new or remanufactured? Either way, I suspect the master cylinder is bad. Please report back once you get it sorted.

JeepWoman

Drove it for a about 30 minutes, let it sit overnight. Used the remaing brake fluid the next day, and pressure bled it again. And got more bubbles from the right rear. The other were all normal streams. The pedal now is almost exactly where it was prior to doing anything. I'm happy with it now, and can feel the difference.

bad_idea

Nice. Glad it was an easy fix. Brakes can be aggravating to get right.