I found that Prestone has a silicate free coolant that is good for aluminum engines and radiators. The ones with silicates have a tendenty to destroy the aluminuminimuinmuimnnuimnn. Didn't know that Now I do And so do you
I drained out all the pink Chinese coolant. I used a turkey baster to get what was in the overflow bottle. Then I filled it up with plain water, ran it till warm, drained and repeat till clear. It took three flushes. Then I filled it with the prestone silicate free.