I am a proud new owner of a 2012 F150 XL with 209,500 miles. This truck has the 5.0 L 8 cylinders engine, 2WD. I want to perform some maintenance myself. I changed the oil and air filter last week. Job for this weekend is the coolant flush. Can you help with some tips? what type of 50/50 coolant do you recommend? use distilled water to clean the inside? Thanks for your help!