Brakes hear air?

Hi, new to the site, just bought a polaris wheeler a few months back. Nice machine, 2012 sportsmen 500HO.

I’m currently having an issue with the brakes. I only have brakes when i press the lever and the foot pedal at the same time.

If I just push the lever in or just push the foot pedal in it does not do anything at all.

If i push in the lever I hear this hissing sound. I can’t really find where its coming from, sounds like its in the middle of the bike at the bottom. I tried several times. I just replaced the rear brake master cylinder because i though that was the problem. Its not, any ideas would be appreciated.