Dear Tom and Ray:

I recently had the radiator replaced on my '85 GM Van. I got 13 years out of it, so I really don't have much reason to complain -- but I will anyway. I regularly had the radiator flushed and the coolant replaced. I'd say I did this once every two years. Did all this flushing do any good at all? Or does it just provide full employment to people in service stations? Is it worth changing the coolant if the radiator is due to rot out from road salt and corrosion anyway? -- Tad

RAY: I'm sure the coolant flushes DID do some good. While it's true that in areas of the country where they salt the roads, radiators DO tend to rot from the outside rather than the inside. But there are other, critical reasons for flushing the coolant, Tad.

TOM: Right. Remember, "a radiator does not a cooling system make," as Henry Wadsworth Longfellow was fond of saying.

RAY: You flush out the coolant to prevent corrosion in the coolant from harming the rest of the engine. Every time the engine runs, the coolant travels through passages
in the cylinder head and engine block. And if there are rust particles in the coolant, deposits can build up on the walls of these passages -- kind of like cholesterol builds
up in your arteries. And if enough crud builds up, it prevents heat transfer and leads to chronic overheating.

TOM: Which leads to a melted engine.

RAY: And then you really would have something to complain about, Tad! So you were right to flush the coolant every couple of years. It was money well spent.