put some new brake fluid is on max level but the brake goes to the floor

Hello,

After changing the caliper, did you bleed the brakes?
If the brakes did not get bled it is good chance that there is air trapped in the line and that is why the brake goes to the floor. As the air will compress and will not provide pressure to the pads.

Here is a helpful guide of how to bleed the brake system:

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

Please let me know of any questions.
Thank you.