Driving home last night and the temp shot to red. Pulled over and found a leek at bottom of hose/rad. I put 2.5 litres of water in it to get me home. When I topped up this morning in the expansion tank the water stayed in the tank, and did not fill the system. So could not check leak at the bottom. took the rad off and checked thermostat. Thermo ok, no leaks in the rad although I,ve not tested it under pressure. I can,t fill the rad through the expansion tank! The tank fills up and thats it, should it transfer the water into the rad? I think it should. Any help is appreciated as I need to be mobile by tuesday. Thanks