Guys: can I use a radiator flush.

Flushing additives are typically used for half an hour to a day to loosen corrosion and scale in the cooling system just before the flush. We never used them at the Chrysler dealership I worked at. All we did was drain the old coolant for recycling, then connect the flush machine to run water through it in different directions. If the force of that water didn't knock something loose, it wasn't coming loose. The main goal of flushing the system is to get the acids out that normally build up in the system over time. The additives that neutralize those acids wear out in about two years. Your new antifreeze will have those additives in it. That's why many people opt for a simple drain and refill rather than the more expensive flush.