Coolant - mix or not?

[Oliver S.]

Hello,

I've heard that coolant should not be mixed if you don't know what type it is (ethylene glycol - as far as I know on older Corvettes), even if it's the same color. Is this true? Suppose, in this case, you work on the cooling system and drain some coolant, but you don't know what type it is. What is to do? Flush the whole coolant or refill it with the collected, drained one?

Regards
Oliver

[Duke W.]

Re: Coolant - mix or not?

OAT blends (typically red like Dexcool), should not be mixed with IAT (green) or HOAT (yellow).

Color is a guide, but not absolute.

Drained coolant can be reinstalled in the cooling system after the work is done - assuming it's not expired. Cooling system work that requires partial draining is a good opportunity to do a change if the antifreeze is close to the 2-3 year expiration.

If you're not sure, just do a complete flush and install Zerex G-05, which is a HOAT and the best current technology to replace "green".

All of these are ethylene glycol based. The difference is the corrosion protection chemistry and organics should not be mixed with inorganics or hybrids.

Lots of info in the archives if you serach the acronyms.

Duke

[Clem Z.]

remember you can not just flush the old

anti freeze down the drain you must depose of it properly. you must pay $$$$ be a good keeper of the earth!!!

[Duke W.]

Re: remember you can not just flush the old

That's not necessarily true.

Everyone should check with their own community haz mat officials (usually in the fire department) to determine how to properly dispose of used antifreeze. Where I live it is okay to dispose of it in the sanitary drain system because we are connected to a state-of-the-art sewage treatment plant that removes heavy metals and breaks down the glycol, however, it is preferred that people collect it and take it to the local recycling center where we take used motor oil, and that's what I do.

Definitely don't dump it into a storm drain system or a septic tank system.

Duke

[Oliver S.]

Re: remember you can not just flush the old

I'll reuse the drained coolant and before winter when the oil gets changed by a garage the coolant will be replaced, too. This spares me trouble with both.

Regards
Oliver