Coolant flush problems on a 2005 ram 1500 3.7 l V6
I just bought a truck and I am doing a coolant flush however whenever I open the petcock I am only getting about a fifth of a gallon of coolant to drain from the radiator. The first time I opened it I thought okay well it had been sitting up for a long time so I filled it up with water distilled water and went to drain it again and I am getting still only about a fifth of coolant to drain. I don't know what to do next can somebody please give me a pointer because I don't want to just keep putting water in there if I can't drain it anymore. This is the last thing I need to do before I get it on the road because it drives perfect it's at $112,000 miles and I'm just ready to get this thing on the road