if the pedal is hard and staying hard, it could be the sensor that fits in the abs pump, this went on my saff and the brakes went rock hard, you can pull the rubber boot back on the plug and feed a live straight into it for 30 secs to pump it back up and try it, this will last a while for you to try, don't leave the live permantly on thought, you'll over load the pump and blow the seals!