I've thought I needed a new radiator @ least twice in the 3 years I've owned my '99 Astro Van, but my buddy Reggie, a very good BY mechanic, told me I didn't!! The 1st time he cleaned it out using 409 (I think), but then he put anti-freeze & tap water back in it. He's on a well, and we live in Central Florida, so any 'tap' water has a heavy mineral content in it, esp. a lot of lime, since all our aquifers run through limestone deposits. And now my radiator is heavily sedimented with rust again. Time to flush it out & replace all the anti-freeze and water (50/50 mix is good enough for this area of Florida), but will use DISTILLED WATER this time!!