Which antifreeze for copper radiators?

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Kestas

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Which antifreeze should I use for my 71 Cutlass that has a copper radiator and heater core? Some time ago I read that for systems that have copper, brass, and solder, silicated antifreeze (like the old green stuff) works best in protecting these metals. Can anyone verify this?

For all my other cars I use G-05 antifreeze.
 
I wouldn't consider using Dexcool on a system that "breathes". I'd only use it on a system that has a pressurized overflow tank. My car is stock.
 
GM used dexcool in systems that "breathe"... with a non-pressurized overflow tank. Specifically, in my '01 Lumina. The first thing I did when I bought the car was rid it of the Dexcool.

I have G05 in everything (two GM 3100's and an old F150)... and I think it'd work just fine in your Cutty.
 
I wish I could dig out the internet article that mentioned silicated antifreeze works best with copper radiators by protecting the solder, brass, copper, or one of these components in the system.

Keep in mind that my system is "antique" in terms of the materials used. Though some modern systems may have copper and brass, I doubt that leaded solder is used in manufacture of these systems.

On the other hand, G-05 has been around for at least 20 years (at least for Mercedes). I don't know when the lead was removed from the systems, or if G-05 was ever specified in leaded systems.
 
G-05 has silicate.
If you look on the Zerex website, you can find out how much they use.....and compare it to how much is in their "traditional green".
 
Labas Kestas,

I think you have a real challenge ahead of you, but your choice will probably be dictated by the products available. I understand that the major problem seems to be with the solder corrosion, with the older lead types being worse.

First, you realize:

1. silicate is an aluminum protector.

2. Today's "conventional" coolants are different (low silicate) chemistry than the old Prestone type high silicate coolants. So, are the authors referring to the old or new "conventional" coolant?

Here is one article by Paul Weissler that states "conventional" coolant SHOULD protect copper/brass radiators better:

http://findarticles.com/p/articles/mi_qa3828/is_200408/ai_n9453107/pg_4

Here's another article recommending G05 in copper radiators:

http://www.csfimports.com/tech.htm#antifrz

Here is one article that says NOT to use OAT in copper systems:

http://www.aa1car.com/library/2005/us90554.htm


Google Paul Weissler and/or see if you can track him down, since he seems to be a guru regarding this subject.

The Zerex site (excellent info) and the Texaco/Havolene site tend to point people towards the "conventional" coolant for all pre 1995 autos. There seems to be little info about G05 use in old vehicles - so, user beware IMO.

Viso gero
 
Aciu doitmyself,

Those articles help me make an informed decision. Paul Weissler's writeup seems the most tehcnical and comprehensive. Given the info, it seems I'm best off using conventional American green and change it out every four years.
 
Give it some time. Coolant chemistries that are "off" don't show problems until well into the future... even though they'll do a good job cooling.
 
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