During my yoot on the family farm this seemed like a never ending task. Blending thick green antifreeze with water after draining and saving the old antifreeze. Between the tractors, trucks, and cars the big metal milk can of used antifreeze used to stay pretty full. Why save the old? Well, to save time if something had a small leak. I seem to remember we eventually took the old stuff some place. Today we would say they either recycled it or disposed of it but back then we just said “they took it.”

I’m sure flannel wearing socks-in-sandals crowd will gasp in horror, but, during the 70s and early 80s, if something had a slow external antifreeze leak which couldn’t be fixed by a simple hose clamp tightening, fixing it waited until you had the time. If it was an internal leak (leaking inside the engine showing up in the exhaust and/or oil) you had to make a decision. On older engines which didn’t have all of today’s sensors or tight water passages in heater cores, you could dramatically extend the useful life with Aluma Seal Radiator Stop Leak. Even if it didn’t work you weren’t out much as you were pulling the engine anyway. On today’s engines like the 4.7 High Output in my 2002 Jeep Grand Cherokee Overland reports from the field in the Jeep forums is don’t try any form of coolant system sealant, especially if you ever want heat again. Replacing the heater core in that thing is a remove the entire dash situation.

Everyone has heard the old automotive maxim

Change your oil every 3 months or 3000 miles.

When all we had was dead Dino oil with simple additives this was gospel. If you didn’t do it your engine died an untimely death. Of course, back then, actually getting 100,000 miles out of an engine was a major achievement. Today, with synthetic oils and better metal alloys many drive trains last 300,000 miles with regular maintenance.

During my youth there was also another maxim

Flush and fill your coolant every 2 years.

Back in the day we had to hand blend antifreeze with tap water to a 50/50 mix. Not many people were actually good at getting the mix to 50/50. If you got it too thin during hard winter your coolant would freeze popping out freeze plugs. In extreme cases it would crack a head or block.

The real problem with having Joe blend his own 50/50 mix had to do with the quality of tap water. All you have to do is see a few commercials on television for the rash of products out there to remove rust and lime scale in your home to realize most tap water isn’t fit for long term use sealed up in an engine. If you some how miss the commercials driving past a major super market or a rural gas station seeing the pallets of softener salt, many with rust or other inhibitors, should tell you tap water has a lot more in it than just water. There used to be many shops which offered radiator rodding services. Most auto supply stores also sold various coolant system cleaners. You would drain your cooling system, fill it with water, then add this little bottle of cleaner. After running the engine for about 5 minutes you would drain again seeing lots of calcium and other nasty looking stuff come out.

Today’s automotive service schedules, those things in the back of your owners manual that you never read, tell you to flush and fill your coolant at previously unbelievable intervals. For my 2006 Toyota Avalon it is every 100,000 miles.

Was the old maxim wrong? No. Much of the 50/50 mix stuff you purchase today is made with distilled water containing no or minimal amounts of minerals. Back in the day most do-it-yourselfers were too cheap to buy distilled water which is what lead to the 2 year maxim. Yes, the corrosion inhibitors included in antifreeze have gotten better as well, but the bulk of the problem was caused by minerals in your tap water.

Now we get to the gist of this post.

How many of you actually looked at the service schedule for your ride?

How many of you have driven well beyond 100,000 miles without changing your antifreeze?