Once again I am turning to those learned members of Arrse for your expert advice. I have a 1999 Mk1 Ford Focus 1.8 Zetec and have come back from a 2 week holiday to find the brakes are next to useless: spongy as hell and bring the car to an ever-so-gentle stop with the foot to the floor. Prior to going on leave there were no problems whatsoever. I don't check my fluids as often as I probably should but it wasn't that long ago, and there have been no stains on the driveway. There is definite braking taking place, just with far less effect on the inertia of the car. I looked in the fluid reservoir to find a puddle in the bottom so topped it up with DOT.4. Whilst doing so half a dozen or so bubble rose to the surface. This made no difference to the brake performance so I've done a little more investigating. With my foot hard to the floor I could hear and feel one of the tyres locking up so stopped to check which one. It turns out the near-side front tyre is locking up and the disc is baking hot while the disc on the front offside is barely warm. Hand brake works as expected. Any clues as to what has gone wrong? Regards, FBG.