Coolant Use

i had a cracked head and it must have been between the jacket and cylinder coz there were none of those usual tell tale sighns but it would bubble into the overflow. I cant think of any reason a head gasket would go on a 100k vehicle except overheating. Small radiator leaks can evaporate without leaking but not 1l in 70k wouldnt have thought

Had the Prado since early 03 with 53000km. Ex gov with full history and dealer servicing. Head was perfect on testing, gasket was leaking, but the coolant is still going. The vehicle has been serviced as to the book. Has had the factory coolant etc, but just check what oil some dealers use. Tested again today, wont hold pressure and still no signs. Sump is still full of ONLY clean oil, no coolant in there. Driving me nuts but Ill eventually find the problem.