Why do brakes go to floor after bleeding on 09 Honda Odyssey?

You said you replaced the calipers. Are the bleeder valves on the top or the bottom? If they’re on the bottom, you have them on the wrong side, and it’ll never bleed.

Probably sounds crazy but if you don’t have access to a scan tool to bleed abs then I usually take vehicle to the nearest dirt road and apply brakes enough to cycle abs to engage. Just a few times usually does it.

Also, having someone applying brakes 4 or 5 times before you open bleeders helps relieve air too.

Obviously, make sure you have some brakes before trying the dirt road application.

Had this exact problem yesterday, and now I have perfect brakes again.

You don’t need a scanner, sounds like you still have air in the system, bleed again. When pumping brake pedal to bleeding only do half strokes as pushing the pedal to the floor can ruin master cylinder, as the sealing cups extend past the sludge line in the master they can loose the ability to seal.