Here's a longshot. Is it possible the front calipers were installed backwards (I mean left side installed on the right, and vice versa)? Please check the location of the bleeding nipples on the calipers. They should be located below the brake line on the caliper. I once read about a guy who replaced the calipers on his jeep, and he couldn't get any pressure in the system because he installed the right caliper on the left side and the left caliper on the right side. He kept bleeding the system and took the calipers back to the store a few times, but no luck; he couldn't get any pressure. Reverse installation of the calipers by the jeep guy caused the brake bleeding nipple to be located above the brake line, and no amount of bleeding would get the air out of the system because air would always be trapped above the fluid line in the caliper.

When I installed steel braided brake lines and performance friction carbon metallic pads on my 2000 4Runner Ltd a few years ago, I didn't plug any of the brake lines, and my master cylinder went dry. I pressure bled the system a few times using my Motive Products pressure bleeder, and the brakes work fine.