The Stovebolt Site Forums The Shop Area General Truck Talk Antifreeze

Hi All,
Starting to think of my last two driving months of this year and maintaining our 1952 Chevy 1/2 ton. My question concerns the necessity of changing antifreeze. I live in Michigan, drive 500 to 1000 miles each summer and use the traditional "green" antifreeze. The antifreeze still looks fresh with no floating particles or staining and checks out good for freeze protection. It has been in our truck for 7 years and from what I'm hearing I am past due for a change. Your opinions would be appreciated. Thank you.

Given your miles driven, and the appearance of the coolant, and it checks out for protection, I would not change it.

Thank you, Tim.
My thoughts also. Appreciate you taking the time to share your opinion.
Chuck

To replenish the rust inhibitors and other additives that might have gotten a little tired, how about draining a gallon or so and replacing it with a 50:50 mix of antifreeze and water? A 50% mix protects to -37 degrees F., so there's not much of a reason to use a stronger mix unless you're in Fairbanks Alaska or somewhere similar. A 70% concentration is the max, since pure antifreeze gets slushy at +19 degrees. It takes a little water in the mix to kick off the freeze protection.
Jerry

Oh, hadn't thought of that. Makes good sense. Thank you, Jerry.
Chuck

At $12-14 per gal. of concentrate, I think it’s cheap insurance to drain, flush, and completely change with fresh antifreeze. Remember, it serves as a coolant also, and the heat breaks down the chemicals much more than the cold does. The rust/scale inhibition factor is another function of antifreeze, so as Jerry says, putting in fresh provides superior protection there as well. Antifreeze also acts as a lubricant for the water pump. I think you’ve gotten your money’s worth after 7 years!! Time for some fresh chemicals.

Thanks you Tim, Chuck and Jerry,
Greatly appreciate the advice.
Chuck 52

Coolant (antifreeze) contains more chemicals than just ethylene glycol and the corrosion inhibitors are consumed over time. The new universal coolants have better corrosion inhibitors now and are good for 5 years unlike the old green coolant that was only good for 2 years. Use distilled water and mix it 50/50 with the coolant.

I would also do a citric or oxalic acid flush to remove any rust and scale. See Cooling System.

Thank you, Frasco.
Chuck 52

It's a 70/30% ratio here in the scorching desert

If you're talking 30% antifreeze for economy, a stronger solution actually increases boiling temperature as well as reducing freeze temp. IIRC, a 60% glycol solution gives the lowest freeze point, As Jerry said, even stronger solutions start increasing freeze (or slush) point. Those poor souls in Fairbanks have to use freeze plug heaters overnight to be able to crank them over. I've heard stories of people driving away from their tire treads when they froze to the ground. I've experienced the square tire symptom, but never lost tires to the cold.

Be careful about type of antifreeze to use.

I saw a report that stressed to use only the old green stuff. It said the modern antifreeze attacks the solder on radiators causing leaks.

Napa & others carry antifreeze that are labeled for older cars (I think 95 & older).

Just a heads up......

Where does a guy get citric acid to do the flush?

Your local parts store will have several flush products, if the system looks pretty good a light duty cleaner, back-flush, drain, rinse, fill with 50/50.

Rebuilt a 235 last fall, filled with water and did a test run. Drained and worked on resto all winter and will be ready to fill with antifreeze soon. Would like to put cleaner in and flush as you said. Thanks for the tip. Bill

I just cleaned and replaced the coolant in my 2005 silverado with prestone green. I've "heard" many stories of how the Dexcool tears down the seals ect. Not sure if it's true or not, but I don't have any leaks, yet.

I see all sorts of problems with cooling systems that use Dex-Cool, mostly corrosion-related. It was originally developed to be more compatible with aluminum than the green stuff, but apparently they didn't test it well enough for long-term use. Older systems, especially the ones with copper radiators, really need to run the plain old green antifreeze. All my vehicles get a 50/50 mix with water- - - - -if that's ever too weak for Tennessee, I'm heading further south in a hurry! Since the coldest recorded temp in our area was -17 degrees F. I think I'm pretty safe!
Jerry

I always use distilled water when I uses 50-50 mix. Had some unusual corrosion problems.

Ed

That's what we use up here! So if that's too weak for Tennessee then we're all in trouble!!

As Spotbiltxo stated as i was thinking it. Antifreeze also lubricates the water pump. You got your time out of it. Change it and worry about it in 7 more years. JMO