I read in an original instruction manual it was best to use the glycol type anti-freeze. I'm assuming it's the same stuff we have today.

However, I also recently read somewhere that todays antifreeze is not safe for those old 4 cylinders because they are not high pressure systems and the anti-freeze will deteriorate the radiator.

Can anybody shed some light on this subject.

Do not use the Dexcol red anti-freeze.Use the conventional green glycol stuff.

Thanks.

Gene what is your opinion of the Red Dexcol for the 95 and up GM vehicles?... I have changed it every three years and another one is due now on my 95. I used the regular green antifreeze coolant on the older vehicles, but have the red in the 95 and 01, (Not GM brand but a major company brand)

My opinion--gathered from many GM techs as well as all the reading material available........

In the first years of its use some techs blamed every cooling system problem on "that red junk"-Water pumps seals, heater core leaks and plugging up of cores.I was of the opinion back then that I would never use the stuff.
Now after 10 years of experianceand more rational thoughts I have decided to continue to use it in my 2000 GM car.
From experiance as well as info. from GM its very important to have an completely sealed,air tight cooling system and to keep the coolant reserve bottle fill to the proper level.A good radiator cap is a must.If air does enter the system the coolant will cause a brown mud to form in the bottle as well as around the filler neck of the radiator and cap.
Its also important to have an air tight system with green antifreeze,such as no leaky water pump, etc. but in the older cars the upper tank of the core is a sorce of allowing oxygen into the system.
The 5 year , 150,000 mile life of the red antfreeze appears to be no problem from the cars I see being serviced.....but most cars develope some type of coolant leak efore that time and the antifreeze will get "renewed".
.More techs approve of it today now that they understand it limitations.
With the old green stuff I usually change the coolant in the old cars every three or four years due to the fact that they are driven little in the time span and the coolant ,because it has not been heated to a high temperature, will last longer....don't know if it true or not but it works for me.
The advantage of the red stuff in a modern car is the longer life.The coolant in many modern cars is almost impossible to change without a "machine" used for that purpose.Changing has become a major operation.
Just as the longer life of spark plugs.Sure glad they don't need to be changed every 10,000 miles as they did years ago with the leaded gas and no platinum eletrodes.

And NEVER mix dexcol with the green glycol. Your entire cooling system will be jello mud...
Gene is right about the new cars having such a sealed system nowadays. You have to use flushing machines on todays cars, and it is a rather lengthly process. Trapped air is also a major problem after flushing todays cars.

I did that in a 96 Roadmaster that we bought used, I added some Red anti freeze when a cold snap was on the way, I never suspected the one year old car would have anything else, but it had Walmart green in it, I discovered it after I poured enough in to see, it turned into brown mud and took me a full day of flushes, and refillings to clean everything up. I later asked the P.O., a widow of a local rancher what the heck she put in the radiator, she said" Why Windmill water".. it is the best tasteing water in the county!"
I never ever really trusted that car afterwards, and when the Buick, Chevrolet, Cadillac and GMC dealer wanted the Roadmaster back for one of his favorite rancher friends, guess what?.. I reluctantly let it go, for a good price!

In many areas its better to buy the pre-mixed coolant....the water they add is more metal friendly.

If I want to buy a gallon of distilled water, I usually pay around 85 cents a gallon and mix it myself, but that is a good point, never use common tap water....I can't beleive some folks even drink that stuff with out any Old Charter or Jack Danials to cut the taste! YUCK!

Hi from downunder
A question for Chev nut
I use the green glycol in my 28 where I just replaced the original honeycomb radiator core with a NOS honeycomb core. Recently my water pump sprung a bad leak through the packing and must have happened not far from home as the 28 didn't get too hot. A week later I noticed this green coolant on my garage floor which let me know of the leak.
But, and here's the crunch, where the green coolant dripped from the water pump onto the timing case cover (which hasn't much paint as the 28 has not been restored) the area affected by the water caused the timing cover to turn rusty and I mean RUSTY.
I'm reluctant to leave the green coolant (a leading reputable brand) in my new honeyconb core, let alone the engine block.
Recent discussions with Ozjim suggested I use pure eucalytus oil as a rust inhibitor instead of the clycol. In our warm climate we don't need anti freeze, but I don't want my block to rust from the inside.
I'd appreciate your comments
Chris

All glycol based coolants sold in this country contain rust inhibitors.Are far better to have in system the just water.
Have no idea as to what eucalytus oil is and Glycol is far better than the rust inhibitors we have in this country.

Chipper is very informed in this area - when he gets back he will have a professional explaination.

I know what a eucalytus tree is and am sure the oil comes from its leaves.....

I think that Eucalytus oil is the stuff that is in Campho-Phynic, and it is good to put on a sore lip, or to unstuff your nasel passages.

yes sure is ,and you boil the car on a hot day is smells good too! Seriously though i have used the 100% pure eucalytus oil for the past 20 years first you need to kleen the system and then get the motor warm and you should only need about a soup spoon full mixed in to the radiator and yes you should top it up from time to time , my 28 has run clean as a wistle for all that time Jim

Ok, so you don't use a cooling system 100% full of oil, just add it to the water in the radiator?

I use only distilled water mixed 50-50 with Zerex, Peak, or Prestone...the green stuff in the older cars. I have wondered what grade of water is used in the Ready-mixed diluted coolant that is being sold at auto stores?

yes mack thats right you only need a small amount mixed into a warm radiator ,why I said 100% is eucalytus oil is sold in various forms for example concentrated ,or pure .I have only ever used the 100% pure oil as that is what I was told to use by the radiator man 25 years ago and to date I have not had a problem

From my experience with modern glycol based anti freeze/anti boil solutions,you need to mix them in the EXACT ratio's suggested by the manufacturer(so you need to know your cooling system's capacity),otherwise if not mixed properly,the solution will become acidic,and cause lot's of problems with the 70 + older block's and heads.
A mate had a similar problem with his 1929 Pontiac Sedan,and it was caused by the incorrect mixing ratio of water to glycol.It went acidic,and opened up a lot of small pin holes in the rear head.
The best idea as ozjim suggested,would either be to use a 100% pure grade of Eucalyptus Oil,or just a plain corrosion inhibitor in the water.
I just use a plain anti-corrosion inhibitor in my 1928 Truck and my 1929 Oldsmobile Sedan,and have had no problem's at all.

Kevin.

From my experience with modern glycol based anti freeze/anti boil solutions,you need to mix them in the EXACT ratio's suggested by the manufacturer(so you need to know your cooling system's capacity),otherwise if not mixed properly,the solution will become acidic,and cause lot's of problems with the 70 + older block's and heads.
A mate had a similar problem with his 1929 Pontiac Sedan,and it was caused by the incorrect mixing ratio of water to glycol.It went acidic,and opened up a lot of small pin holes in the rear head.
The best idea as ozjim suggested,would either be to use a 100% pure grade of Eucalyptus Oil,or just a plain corrosion inhibitor in the water.
I just use a plain anti-corrosion inhibitor in my 1928 Truck and my 1929 Oldsmobile Sedan,and have had no problem's at all.

Kevin.

I mix mine by pouring a 2 gallons of Zerex and two gallons of distilled water in a clean plastic 5 gallon bucket and letting it mix, then pour it into the radiator, and when the cooling system is full I pour the leftover portion back in the antifreeze containers and mark them 50-50 MIX. That way I do know the mixing ratio.

P.S.
I have been told there is a wrong way, a right way, a military way and a M/W way!

any issue using water that's been deionized or "purified" by reverse osmosis, as opposed to distilled?..


epi

Anyone besides me ever used water based machine cutting oil? Often used as a water pump lubricant.

I've been using it in my 28 coach with original (assumed) honeycomb radiator for 5 or six years now. Doesn't evaporate like glycol does in an open system.

Chevrolet, I don't know about that, i don't find RO water in the grocery store where I buy the distilled water. We have a RO unit here in Midland because of the sorry tap water but I barely drink it without disinfecting it with some Black Jack or Smirnoff.

macky,

no, I don't buy it either...I have access to a ro unit and bring my own jugs to fill...


epi

Oh, my oh my. Don't know where to start.
Glycol based antifreeze/coolant contains several additives to provide corrosion protection for all metals used in modern cooling systems. That includes brass radiators, aluminum steel or cast iron blocks and heads. There are also acid scavengers or buffers.

It is recommended to change the coolant every two to five years depending on age and condition of engine. Heat, air, exhaust gas, oil, lubricants and other contaminants will shorten the life of any coolant. Water is ok as long as full range inhibitors are added at the correct level. Too much or too little can lead to a problem.

Soluble oils are not recommended as they only marginally protect metals from corrosion, can shorten the life of hoses and seals, inhibit heat transfer. Older systems will typically be more compatible with soluble oils than newer ones. Like any automotive chemical product, there are people what swear by any given product and others that swear at them. Which depends on many factors.

There is no practical difference between de-ionized, distilled and reverse osmosis water. Each has little or no dissolved solids. Softened water is a completely different situation. It is loaded with dissolved solids. So are most tap waters. It is these dissolved solids that coat the radiator and engine coolant passages reducing heat transfer. Typically the hotter surfaces inside the engine are the first to have deposits form. It reduces the heat transferred to the coolant, increases exhaust temp and internal engine temp. Coolant temperature stays the same or might even drop a little. Open systems that typically loose coolant are particularly venerable. Any solids added with makeup water just add to the deposits. Eventually the coolest (low flow) tubes in the radiator become restricted which accelerates the deposit of solids. Then the coolant temperature begins to rise and finally boiling. The damage is done before the owner realizes it.

If coolant is lost due to a leak then pre-mixed make up is best. If by boiling or vaporization then the glycol concentration will continue to rise if pre-mixed is used. Anything over 70% glycol is asking for a problem.

I would expect that de-ionized or condensate (distilled) water is used in the pre-mixed coolant. All major manufacturers know the hazards of using tap water. I know that the company I used to work for used condensate.

Did I answer all the questions? If not let me know and I will attempt to set things straight. I did not work for the largest brake fluid and no. 2 coolant manufacturer in the automotive product department without learning a thing or two.

chip,

as always, thanks for the information and explanation...


epi