Adding rust inhibitors vs. new Anti-freeze

[Bob_Young]

My old Ag tractors are protected with permanent antifreeze. As things currently stand, none of them see much use over a year; maybe 20 or 30 hours tops. Rather than drain and refill with fresh anti-freeze every 2 years, I've taken to adding cooling system rust inhibitors periodically. It's quick, simple, less messy and less expensive.

I wondered if anyone else here is taking this approach or if anyone has experience, good or bad, with using corrosion inhibitors in place of fresh antifreeze.
Bob

 

[RalphVa]

I bought a VW that was 5 years old. The VW manual says it's permanent antifreeze, there for the life of the car. Well, I changed it anyway. It was bright and clear, no evidence of any degradation at all.

Checked my maintenance books on both my Toyota and Benz. Been 3 years since I changed theirs. Bought new antifreeze: $23/gallon @ Toyota and $25/gallon @ Benz. Both drained beautiful and bright and clear, Toyota redish clear; Benz a little yellowish clear.

So, based on my experience and the current high price of antifreeze, I'm going to 5 year change intervals on anything with long life antifreeze in it.

If you go with the standard Prestone or other non-so-clear-to-begin-with, dark-color brands, you might want to continue changing at 2 years. Buy quality at $23-25/gallon and go to 5 years. Done similar on my engine oil. Have gone to yearly changout or approximately 6k+ miles, but using $5-6/qt. Mobil 1 vs. $2/qt. dino stuff. It's just easier on my getting-old bones, too.

Ralph

 

[kmdigital]

Bob, I tend to agree with you. Unless the coolant is discolored or rusty, adding rust inhibitor periodically instead of changing as often it will do virtually the same thing. I did that for years with several vehicles I had, and they stayed nice a clean.

It would be best though if you used silicate free antifreeze, like one of the newer 150,000 mile, 5 year brands. This applies to most engines, but for some reason some mfgs (like Ford in the earlier PowerStrokes) don't recommend these coolants due to potential issues with rubber o-rings.

The reason for using this coolant has something to do with silicate drop out, which is eliminated by using a silicate free product. I believe that it is the silicates that often plug up radiators, heaters, etc, if the antifreeze isn't flushed regularly.