I had a hard time bleeding brakes on my Z after installing the Toyota 4x4 calipers. Here is a copy of the post I did back then: I feel your pain. I had one hell of a time bleeding my brakes after putting the conversion on. Make sure you thoroughly bleed the master cylinder first. Then move to the right rear, left rear, right front, and then left front. I also had to crank up the rear drums a bit more. If that doesn't do it, try this racer trick that Rick taught me. Once the brakes are bled all around, go to the right front, remove the outer brake pad, open the bleeder screw, then take a pair of lock jaw pliers and force the pistons in. Be careful not to push them past the seals. Put the pad back in and do this to the inner brake pistons. Then repeat on the left front. I was amazed at how much extra air I forced out of the calipers. Once I got it bled correctly, the brakes are killer! I also highly recommend installing SpeedBleeders on all 4 corners and the master. It will make your life much easier. Hope this helps! Marty