Which hand is stonger, a power flush or reverse flush?

Dear Car Talk

Dear Car Talk | Jun 01, 1991

Dear Tom and Ray:

Is there a difference between a power flush and a reverse flush? Should one of these be done periodically?

RAY: I think the difference is that a power flush beats three of a kind, Ben, and a reverse flush doesn't.

TOM: Actually, Ben, most power flushes are in fact reverse flushes. A power flush is when a cleansing agent is forced through the cooling system. And in most cases, it's forced through in the opposite direction that the coolant normally travels.

RAY: Power flushes used to be important back in the old days before cars had permanent antifreeze. People used to fill their radiators with an alcohol mixture in the winter, and plain old water in the summer. The problem was that the water caused rust and corrosion, and tiny metal particles used to clog up the passageways in the cooling system. The power flush was necessary to clean that stuff out.

TOM: But now we have antifreeze with rust inhibitors that stays in the cooling system year round. So rust and corrosion aren't really problems anymore. On modern cars, all you have to do is drain out the old antifreeze every couple of years, and put some fresh stuff in. And unless you've neglected to do this for years, you should never need power flush.

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