It is the master cylinder assembly - back left of engine bay as you look from the front of the car - just behind the turbo heatshield. Brake pedal is attached to it. You'll see it has three outputs under the reservoir. Front and back outlet are front left and front right brakes. Middle output is for the back brakes. Disconnect the middle and press the brake pedal. If fluid doesn't spurt out you have a dead master cylinder. Get a replacement. If you have a 4X4 I have a spare you're welcome to. Mine is 2WD.

Charlie