I need to flush and change my coolant (02 3500 dually) and have read several threads on just using the flush kit from autozone. My question is if I can't use tap water and must use distilled, can I use tap water to flush the system?? My truck currently has green coolant, when I went to get new coolant I found already mixed with distilled water and the back of the bottle said it was for my engine. Being a newbie (but a little common sense) I have heard that you can't change coolant colors, so called. If you have green, use green. If you have orange, use orange. The new coolant was orange. My next question is, can I use it???? Last question, besides in my neighbors cat bowl, where can I legally dump my old coolant??? Thanks for all the great post.