I have convinced myself that the yellowy liquid (about 4 litres) I drained from the blue tap at the lower right rear of the radiator was not coolant as the coolant in there is blue and it's full up (just tried to fill it (though I am thinking there could be a blocked hose which is causing the a/c not to work). Any ideas? Please help!
Jonathan, UK '97 BMW E39 523i SE Manual
PS - How do you actually drain the coolant then? And where should the yellowy fluid go?