I own a 2001 TDDI Ford Mondeo. Driving in very heavy rain, I approached traffic lights which changed to red and I hit the brakes. The car stopped as normal but the pedal went down further than normal. When the lights went green I pulled away, and up the road I came to more traffic, applied the brakes and nothing. Only with the pedal fully down do I get any braking. I left the car for a while and until the rain had stopped, got in, started the car and now I just get the sound of air whooshing when I apply the brake. I get some braking with the pedal to the floor, but it's too dangerous to drive. Any ideas what the problem could be? The ABS light comes on and disappears as normal.