Christi@n

Hi

Usually i go with prestone concetrate the yellow one in my 95 vette.
From owner manual gm1825m is spec.

Do you use it too? Is a good quality Antifreeze as far as you know??

hcbph

I use Prestone in my 86 but there is a cavat based on what I've read. You don't want to just add Prestone to the existing coolant if it's the GM stuff. From what I read, if you just add Prestone to the existing stuff, they don't play well. It turns into something between slurry and Silly Putty. I had the cooling system drained and flushed before switching to Prestone and have not had a problem with it. I did have an issue with a leaking hose but that wasn't related to the antifreeze, rather the age of the hose.

Christi@n

Yes there were somthing like a green stuff in. When i've replaced it last spring, i've drained all old green stuff, from rad and KS holes, flushed all engine with tap water, then filled with prestone.

Christi@n

Also what is cavat based?

WVZR-1

I believe he meant "caveat" -

Christi@n

never heard anyway

I know OAT, HOAT based, but never heard CAVEAT based

84Z51J

If you had green to begin with, and maintain a ~50/50 coolant/water split, you should be safe from corrosive nuisances & sludge, running Prestone. Red (Dex-Cool) means STOP and do not mix any other color. Some "universal" coolants claim to play nice with even this notorious mucker-upper; I prefer playing by better-safe-than-sorry rules, & stick to "universal" alone

hcbph

So I can't spell at times

Full Definition of caveat

1
a : a warning enjoining one from certain acts or practices b : an explanation to prevent misinterpretation c : a modifying or cautionary detail to be considered when evaluating, interpreting, or doing something

2
: a legal warning to a judicial officer to suspend a proceeding until the opposition has a hearing

Webster describes it better than I ever could. I was using it as the last item in #1

Christi@n

Ah ah ok now i got it.

Caveat based was for your 1986 vette. A warning about to use prestone in your model year

Feel like a stupid... :-)

Christi@n

As matter of fact i was afraid about to use prestone in my car, cause i've just get a worn radiator.

I have new here ready to install. The old one was a copper brass seems. So i was wondering it happened due to the prestone use, since i've flush and refill system about on year ago.

I've not remove old rad yet, however seems that is damaged on tube row or near the tank

c4cruiser

The C4's that used Dex-Cool can be changed to a "green" ethylene glycol coolant but the old Dex-Cool must be completely flushed out of the cooling system. This would mean removing the knock sensors and making sure that all traces of the Dex is gone. This could take 3-4 flushing processes and it probably couldn't hurt to use a very mild cooling system cleaner.

The FSM procedure for a flush is to drain the old coolant, fill with water, let the engine get to operating temp, shut down and drain. Repeat that process 2 more times. While that's fine for using the same coolant type, changing from one type to another will mean doing that a few more times.

The ethylene glycol coolant would still be a 50-50 mix using distilled water. One thing I have found that the concentrate bottles are only a couple dollars cheaper than the pre-mixed coolant. So use the concentrate and dilute it yourself.

Prestone coolant is a decent product and I have used it for years in a variety of cars, but I would not really consider the "universal" stuff. Use either the green coolant or Dex.

Christi@n

My user manual GM1825m as coolant spec. It would be the dexcool spec??is an old spec and I can't find anything about it,

hcbph

It wasn't about Prestone in my car but rather insuring that all the old coolant was removed before switching to Prestone. The possibility of the old and new causing issues without a complete flush is too much of a risk otherwise.

WVZR-1

A search on this forum (C4 generation) for just 1825M furnished 21 threads, 1825-M 30 more, some maybe duplicates (didn't check). There's much to be absorbed both here and the Internet regarding 1825m specification coolant.

Dex-Cool is NOT 1825m

If you've a question about a "specific" Prestone product post the product number - perhaps the bar-code label and a snapshot.

What did you use the last time you flushed? Did you do the KS removal flush procedure? Did you use a cleaner of any sort?

Maybe contact Pakelo Labs and ask if they have a product that meets the GM 1825-M specification.

Christi@n

Two time like a stupid

Christi@n

This is Prestone I've used.
Last time I've flushed removed ks too, then more times flushed with tap water

WVZR-1

I believe the only issue you might have is making SURE you use demineralized/distilled water for the mix.

I think here if using a Prestone brand maybe the PRIME GREEN - maybe!

84Z51J

As long as you do a thorough flush of the recovery tank, block (out through knock sensors), radiator, & heater core, you can put Honda coolant in there and it'll work just fine in the proper proportion (with distilled water, of course).

Antifreeze/coolant isn't voodoo science--they all accomplish the same thing in very similar systems. I recommend universal because it's the easiest to obtain, and add to. Complication-free coolant fills really just comes down to picking one formula, and sticking with it.

mako41

You have pictured an OAT type ethylene glycol coolant, (A Dex-Cool clone) It should not be mixed with other types of ethylene glycol coolants that have different corrosion inhibitor chemicals in them!

If you think your vette was shipped from the factory with GM 1825M spec ethylene glycol coolant, which is an old silicate/phosphate corrosion inhibiting type coolant you are not using the same stuff with that Prestone any/make model refill! GM 1825M spec ethylene glycol was green/yellow in color, and is not the Prestone OAT type coolant you have pictured. I believe PEAK still makes a coolant that meets the old GM 1825M spec, but that is not a long life coolant and should be changed annually.
http://www.peakauto.com/products/ant...th-antifreeze/

Check out these threads for all you what to know about C4 coolant, and plenty of misinformation you don't need to know as well!!

https://www.corvetteforum.com/forums...t-coolant.html

https://www.corvetteforum.com/forums...or-matter.html

https://www.corvetteforum.com/forums...e-choices.html

Christi@n

Readed a lot around, I've got that the most important in to avoid to mix dex-cool or dex-clone with other type antifreeze,

Just I've not got if a dex-cool only can be dangerous too??for head gasket or other parts