We just had to replace the rads on 6 trucks (150's and Rangers) due to the Orange County service shop replacing the Sierra brand coolant with DexCool at the last routine service.
6 months later all had major rad damage (rot) and we had to swap out all the water pumps. The thermostats looked like a blob of frozen Orange Crush and it took 3 to 4 hours of run time on the Power Flusher to clean the crud out of the block on each truck.

The clue was when the Temp Sender began to take an inordinate time to register warm up and when we had a lower hose failure due to object impact damage the cut developed a "stalagtite" of DexCool ooze...

Anyway the stuff is "not good" as Martha the soon to be con would say...