changing coolant

If you do a good cleaning job once ... then every 2-3 years water-flush only (plugs out) & fresh Dh2o mix ... you'll probably never need to clean it again.
http://forums.corvetteforum.com/c3-g...post1568304902
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pull the threaded block plugs & flush thru there too ... IF you have to poke thru rust/sediment OR if much comes out block plugs, THEN also do a cleaning w/strong chemical ... THEN flush thru again ... then refill w/ distilled water & antifreeze.If you do a good cleaning job once ... then every 2-3 years water-flush only (plugs out) & fresh Dh2o mix ... you'll probably never need to clean it again.
http://forums.corvetteforum.com/c3-g...post1568304902
Let me try and put this into perspective.
Here is what settles in the bottom of the block where the plugs are. You can see by the wrench size how big these pieces can get.
What is in the bucket was only on the 10th flush.


Try running water in that bucket and seeing if it cleans it all out. It won't happen. Drill a hole in the bucket bottom and you will be able to rinse it out thru the hole.
Same thing with the block plugs.
BTW, to get this stuff out thru the block plugs, I probably flushed for a couple of hours, filling the block and then emptying it at least 25 times.
Bottom line, if you don't do it right, this stuff will plug your rad, especially a new aluminum core that has much smaller passages.
This is one of the first things I do with any engine I get simply because the cooling system should be as clean as possible.
Then you can chase other problems.
















