If your brake pedal pressure isn't spongy, try removing the brake fluid reservoir cap and add some fluid. I'm not certain about what to use in a 240, but I'd bet Dot-3 would be fine. If the pedal is spongy, I'd take it to a shop fast. The weather in your area is not very forgiving to faulty brakes.
This isn't something you want to delay for very long. Have a tech determine the cause of this problem.