Brakes not completely working
 

I recently discovered that my brakes only half work. It turns out that only the front brakes engage. This is kind of tricky in the winter with the ice and snow (when I would like to have the best braking ability). I have a 1991 Chevy S10 any suggestions would be more than helpful!
Thank you!

Is the brake light on at all?

the brake lights do come on.

Light on means low on brake fluid. Check for leaks.