Can some one tell me what causes injector cups to crack or leak? I recently took mt 02 F250 7.3 in to have the rad flushed and refilled. It has the gold antifreeze from the factory with 140 thousand KLMs on the odometer. When they were draining the old stuff out they called me in to the shop to show me how much diesel fuel was in the antifreeze. After seeing that they put the old stuff back in and refered me to a local shop that specializes in diesel injectors and turbos. I had no idea what had happened because the level in the degas bottle never changed in 8 years. Now this specialty shop is telling me that I may have 1 or more cracked injector cups that would cause this problem. I was told that it will cost anywhere from $1500.00 to $2000.00 to repair depending on if the cups can be removed with or without removing the heads. I have been using a Diablo Sport tuner for 2 years now on the 85 performance tune for better milage. could this have caused my problems or is some one trying to bleed me from some hard earned money. Please Help