Brake light on the dash- help needed

[Tkrysl]

Okay guys I have my first cry for help.

Out of all the things that I had to do on my 72 C15 to get it to pass safety inspection I'm down to the final thing and I cannot figure out how to get this brake light off my dashboard.

The safety inspector failed me because he said my "master cylinder gasket was swelled" and I have the red light on the dashboard. He told me I needed a new master cylinder to get that light to go off.

I replaced the master cylinder with a new one put new rotors and pads and calipers and shoes on the back. I'm a Noob at this so if you have any advice on why that red brake light is on I am all ears because I have to have this thing reinspected Monday morning.

Thanks!