Can concentrate and pre-blended coolants be combined? An easy solution is that you can, having said that never combine IAT and OAT antifreeze with each other. Inspect for leaks or problems: Routinely inspect the coolant hoses, radiator, and water pump for any signs of leaks or hurt. WARNING - To https://arthurxiovb.tinyblogging.com/5-simple-statements-about-types-of-coolant-use-in-mercedes-explained-71050023