brakes feel like they are slipping brake master cylinder?

This could be the issue but here is a guide that will help with this type of issue: It is either caused by a leak or a leak internal to the master cylinder. So I would replace it and retest. Here are the master cylinder installation instruction you have requested. Here is a guide to help you step by step with instructions in the diagrams below to show you how on your car.

https://youtu.be/WDxvEQrMkBg

and

https://youtu.be/w7gUsj2us0U

and

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

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed. Below is the process from the manual that will help with getting this replaced.

hi
my 06 has been a nice car but the other day when i came home the and the brake pedal sank I need a new master can you hep me please? thanks steve

This does sound like a master cylinder or you have air in the lines due to a leak. Here is a guide that will help with this:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

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

Below is the process on how to replace the master cylinder from the manual.

Please let us know if you have other questions. Thanks