Radiator Flushing

[Rich Largent]

Is there a "favorite" process folks use to flush and clean radiators? Are commercially available chemical flushes okay or should I employ less invasive methods? My 29 CCPU sat for nearly two years prior to my purchasing it. I can see a fair amount of rusty sludge around the radiator cap. When first purchased I straight water flushed it several times until the outflush ran fairly clear. It runs great and has not approached overheating.

 

[Tom Wesenberg]

Do a search for "radiator flush" or "radiator cleaning" and you should have a few methods discussed, including my flushing about 4 months ago.

 

[kenparker]

There was a long thread or might I say dissertation about this subject about a month ago.

This past summer i emptied my S/W radiator and poured in 1 gal of pure full strength Simple Green. My block had just been vatted and engine was rebuilt so I was not concerned about rust - the radiator was just greasy and cruddy looking on the inside. Then added the 1 1/2 gal o water and drove her , city drving as well as 55 mph country road driving for at least 30 minuttes. Pulled back in the shop and covered the radiator and ran her another 10 minutes or so at 200 to 210 degrees. When I drained the radiator it looked like dark brown milk shake. It toook a lot of flushing to get the brown out but when finished the inside was copper clean.

To shorten a long story I, in the long run, had to spring for a new radiator. New engine with new radiator would not get over 145 degrees. Finally had to put a termotat in it to get it up to 160 - but she runs fine now. ken