brake fluid

Any idea what has caused this "blue slime" in my car's brake fluid reservoir and brake master cylinder? I purchased the car last August and found the slime when I replaced the rear brake pads, master cylinder and flushed the brake fluid.

So after 7 years of my 77 Camaro being in storage I finally got everything ready to do a test drive. On my test drive I realized I have almost zero brake pedal, it barely catches right at the end. So I take it home and start to try to bleed the brakes, long story short I couldn't get brake fluid...

Can’t find this info. Is there a shelf life for Dot 3 brake fluid? My Dad had a metal container from GM in his garage that’s still sealed with the metal tab and if it’s good I’ll use it if I run out. I need to replace my master cylinder and ordered a Delco casting 409 From Napa plus I’m over due...