I recently bought a 1995 Dodge Ram 2500 utility bed truck since my ford van fired another spark plug into orbit, and I'm tired of fixing it. Before I got it, the seller took it to Sears for an oil change and coolant flush. I asked Sears what coolant they used, and the gal told me, "Well, it's supposed to use Dex-cool, but we put the yellow stuff in." I'm not sure what the yellow stuff is, some sort of universal, I think? What is it really supposed to be, and should I flush it and put the correct fluid in?