Brake pedal goes to floor plenty of brake fluid?

Hello,

When a brake pedal goes to the floor, typically it happens for a bad master cylinder. It could also happen if the brake caliper is bad as well. Also this will be triggered by air in the brake system.

Have you tried to bleed the brakes?

https://youtu.be/w7gUsj2us0U

This can also be a symptom of leaking brake lines. You also need to check the brake booster to verify that the vacuum hose is connected.
If a caliper leaks or has a blown seal it will also make the pedal go to the floor, as all the pressure gets released not having proper seal in the caliper.

You might find these articles helpful:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor
https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

I have attached diagrams for your reference.

Please let me know of any questions.

Thank you.