Hi..can anyone assist? My 2 0 tdi had a water pump go and therefore took to a garage and had a new water pump and timing belt fitted along with all the pulleys etc.. had the car back and runs lovely, however I am now losing a serious amount of water..filling up after every trip. I have checked all the pipes and placed a new expansion tank cap but cannot see any leaking and I can leave standing overnight and on undoing the cap it's still pressurised! It's a head scratcher.. no water in oil no bubbles in expansion tank ,no leaks on matrix radiator thermostat is sealed ....HELP