took the escos out yesterday, came back and parked on the drive to find the header tank completely empty and its contents on the drive.

Had a poke around but can't pin point exactly where its leaking from, its somewhere from the front of the engine, its definately not from the thermostat housing but a bit further down and its leaking all over the pulleys.

Have filled the expansion tank back up and it holds the water until you take the expansion cap off or squeeze the rad hoses.

Anyone got any ideas on what might be leaking?