I have a 2006 silverado 1500 extended cab pickup

brake pedal almost to floor .also wont change from 2 wheel drive.

was fine until i used 4 wheel drive and shifted back to 2 wheel drive.

then brake pedal went almost to floor and service lights for both the brakes an 4wd started flashing. Could it be a fuse?

 

Fuse isn't going to make your petal go soft... Check your brake fluid.

4wd might be a fuse tho.